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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] x86/boot: Merge CPUID policy initialisation logic into cpu-policy.c
commit 8eb56eb959a50bf9afd0fd590ec394e9145970a4
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Mon Apr 3 19:06:02 2023 +0100
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Wed Apr 5 11:47:08 2023 +0100
x86/boot: Merge CPUID policy initialisation logic into cpu-policy.c
Switch to the newer cpu_policy nomenclature. Do some easy cleanup of
includes.
No practical change.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/arch/x86/cpu-policy.c | 752 +++++++++++++++++++++++++++++++
xen/arch/x86/cpuid.c | 817 +---------------------------------
xen/arch/x86/hvm/hvm.c | 1 -
xen/arch/x86/include/asm/cpu-policy.h | 6 +
xen/arch/x86/include/asm/cpuid.h | 11 +-
xen/arch/x86/pv/domain.c | 1 +
xen/arch/x86/setup.c | 2 -
7 files changed, 764 insertions(+), 826 deletions(-)
diff --git a/xen/arch/x86/cpu-policy.c b/xen/arch/x86/cpu-policy.c
index f6a2317ed7..83186e940c 100644
--- a/xen/arch/x86/cpu-policy.c
+++ b/xen/arch/x86/cpu-policy.c
@@ -1,13 +1,19 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <xen/cache.h>
#include <xen/kernel.h>
+#include <xen/param.h>
#include <xen/sched.h>
#include <xen/lib/x86/cpu-policy.h>
+#include <asm/amd.h>
#include <asm/cpu-policy.h>
+#include <asm/hvm/nestedhvm.h>
+#include <asm/hvm/svm/svm.h>
#include <asm/msr-index.h>
+#include <asm/paging.h>
#include <asm/setup.h>
+#include <asm/xstate.h>
struct cpu_policy __ro_after_init raw_cpu_policy;
struct cpu_policy __ro_after_init host_cpu_policy;
@@ -20,10 +26,332 @@ struct cpu_policy __ro_after_init hvm_max_cpu_policy;
struct cpu_policy __ro_after_init hvm_def_cpu_policy;
#endif
+const uint32_t known_features[] = INIT_KNOWN_FEATURES;
+
+static const uint32_t __initconst pv_max_featuremask[] = INIT_PV_MAX_FEATURES;
+static const uint32_t hvm_shadow_max_featuremask[] =
INIT_HVM_SHADOW_MAX_FEATURES;
+static const uint32_t __initconst hvm_hap_max_featuremask[] =
+ INIT_HVM_HAP_MAX_FEATURES;
+static const uint32_t __initconst pv_def_featuremask[] = INIT_PV_DEF_FEATURES;
+static const uint32_t __initconst hvm_shadow_def_featuremask[] =
+ INIT_HVM_SHADOW_DEF_FEATURES;
+static const uint32_t __initconst hvm_hap_def_featuremask[] =
+ INIT_HVM_HAP_DEF_FEATURES;
+static const uint32_t deep_features[] = INIT_DEEP_FEATURES;
+
+static const struct feature_name {
+ const char *name;
+ unsigned int bit;
+} feature_names[] __initconstrel = INIT_FEATURE_NAMES;
+
+/*
+ * Parse a list of cpuid feature names -> bool, calling the callback for any
+ * matches found.
+ *
+ * always_inline, because this is init code only and we really don't want a
+ * function pointer call in the middle of the loop.
+ */
+static int __init always_inline parse_cpuid(
+ const char *s, void (*callback)(unsigned int feat, bool val))
+{
+ const char *ss;
+ int val, rc = 0;
+
+ do {
+ const struct feature_name *lhs, *rhs, *mid = NULL /* GCC... */;
+ const char *feat;
+
+ ss = strchr(s, ',');
+ if ( !ss )
+ ss = strchr(s, '\0');
+
+ /* Skip the 'no-' prefix for name comparisons. */
+ feat = s;
+ if ( strncmp(s, "no-", 3) == 0 )
+ feat += 3;
+
+ /* (Re)initalise lhs and rhs for binary search. */
+ lhs = feature_names;
+ rhs = feature_names + ARRAY_SIZE(feature_names);
+
+ while ( lhs < rhs )
+ {
+ int res;
+
+ mid = lhs + (rhs - lhs) / 2;
+ res = cmdline_strcmp(feat, mid->name);
+
+ if ( res < 0 )
+ {
+ rhs = mid;
+ continue;
+ }
+ if ( res > 0 )
+ {
+ lhs = mid + 1;
+ continue;
+ }
+
+ if ( (val = parse_boolean(mid->name, s, ss)) >= 0 )
+ {
+ callback(mid->bit, val);
+ mid = NULL;
+ }
+
+ break;
+ }
+
+ /*
+ * Mid being NULL means that the name and boolean were successfully
+ * identified. Everything else is an error.
+ */
+ if ( mid )
+ rc = -EINVAL;
+
+ s = ss + 1;
+ } while ( *ss );
+
+ return rc;
+}
+
+static void __init cf_check _parse_xen_cpuid(unsigned int feat, bool val)
+{
+ if ( !val )
+ setup_clear_cpu_cap(feat);
+ else if ( feat == X86_FEATURE_RDRAND &&
+ (cpuid_ecx(1) & cpufeat_mask(X86_FEATURE_RDRAND)) )
+ setup_force_cpu_cap(X86_FEATURE_RDRAND);
+}
+
+static int __init cf_check parse_xen_cpuid(const char *s)
+{
+ return parse_cpuid(s, _parse_xen_cpuid);
+}
+custom_param("cpuid", parse_xen_cpuid);
+
+static bool __initdata dom0_cpuid_cmdline;
+static uint32_t __initdata dom0_enable_feat[FSCAPINTS];
+static uint32_t __initdata dom0_disable_feat[FSCAPINTS];
+
+static void __init cf_check _parse_dom0_cpuid(unsigned int feat, bool val)
+{
+ __set_bit (feat, val ? dom0_enable_feat : dom0_disable_feat);
+ __clear_bit(feat, val ? dom0_disable_feat : dom0_enable_feat );
+}
+
+static int __init cf_check parse_dom0_cpuid(const char *s)
+{
+ dom0_cpuid_cmdline = true;
+
+ return parse_cpuid(s, _parse_dom0_cpuid);
+}
+custom_param("dom0-cpuid", parse_dom0_cpuid);
+
+#define EMPTY_LEAF ((struct cpuid_leaf){})
+static void zero_leaves(struct cpuid_leaf *l,
+ unsigned int first, unsigned int last)
+{
+ memset(&l[first], 0, sizeof(*l) * (last - first + 1));
+}
+
+static void sanitise_featureset(uint32_t *fs)
+{
+ /* for_each_set_bit() uses unsigned longs. Extend with zeroes. */
+ uint32_t disabled_features[
+ ROUNDUP(FSCAPINTS, sizeof(unsigned long)/sizeof(uint32_t))] = {};
+ unsigned int i;
+
+ for ( i = 0; i < FSCAPINTS; ++i )
+ {
+ /* Clamp to known mask. */
+ fs[i] &= known_features[i];
+
+ /*
+ * Identify which features with deep dependencies have been
+ * disabled.
+ */
+ disabled_features[i] = ~fs[i] & deep_features[i];
+ }
+
+ for_each_set_bit(i, (void *)disabled_features,
+ sizeof(disabled_features) * 8)
+ {
+ const uint32_t *dfs = x86_cpuid_lookup_deep_deps(i);
+ unsigned int j;
+
+ ASSERT(dfs); /* deep_features[] should guarentee this. */
+
+ for ( j = 0; j < FSCAPINTS; ++j )
+ {
+ fs[j] &= ~dfs[j];
+ disabled_features[j] &= ~dfs[j];
+ }
+ }
+}
+
+static void recalculate_xstate(struct cpu_policy *p)
+{
+ uint64_t xstates = XSTATE_FP_SSE;
+ uint32_t xstate_size = XSTATE_AREA_MIN_SIZE;
+ unsigned int i, Da1 = p->xstate.Da1;
+
+ /*
+ * The Da1 leaf is the only piece of information preserved in the common
+ * case. Everything else is derived from other feature state.
+ */
+ memset(&p->xstate, 0, sizeof(p->xstate));
+
+ if ( !p->basic.xsave )
+ return;
+
+ if ( p->basic.avx )
+ {
+ xstates |= X86_XCR0_YMM;
+ xstate_size = max(xstate_size,
+ xstate_offsets[X86_XCR0_YMM_POS] +
+ xstate_sizes[X86_XCR0_YMM_POS]);
+ }
+
+ if ( p->feat.mpx )
+ {
+ xstates |= X86_XCR0_BNDREGS | X86_XCR0_BNDCSR;
+ xstate_size = max(xstate_size,
+ xstate_offsets[X86_XCR0_BNDCSR_POS] +
+ xstate_sizes[X86_XCR0_BNDCSR_POS]);
+ }
+
+ if ( p->feat.avx512f )
+ {
+ xstates |= X86_XCR0_OPMASK | X86_XCR0_ZMM | X86_XCR0_HI_ZMM;
+ xstate_size = max(xstate_size,
+ xstate_offsets[X86_XCR0_HI_ZMM_POS] +
+ xstate_sizes[X86_XCR0_HI_ZMM_POS]);
+ }
+
+ if ( p->feat.pku )
+ {
+ xstates |= X86_XCR0_PKRU;
+ xstate_size = max(xstate_size,
+ xstate_offsets[X86_XCR0_PKRU_POS] +
+ xstate_sizes[X86_XCR0_PKRU_POS]);
+ }
+
+ p->xstate.max_size = xstate_size;
+ p->xstate.xcr0_low = xstates & ~XSTATE_XSAVES_ONLY;
+ p->xstate.xcr0_high = (xstates & ~XSTATE_XSAVES_ONLY) >> 32;
+
+ p->xstate.Da1 = Da1;
+ if ( p->xstate.xsaves )
+ {
+ p->xstate.xss_low = xstates & XSTATE_XSAVES_ONLY;
+ p->xstate.xss_high = (xstates & XSTATE_XSAVES_ONLY) >> 32;
+ }
+ else
+ xstates &= ~XSTATE_XSAVES_ONLY;
+
+ for ( i = 2; i < min(63ul, ARRAY_SIZE(p->xstate.comp)); ++i )
+ {
+ uint64_t curr_xstate = 1ul << i;
+
+ if ( !(xstates & curr_xstate) )
+ continue;
+
+ p->xstate.comp[i].size = xstate_sizes[i];
+ p->xstate.comp[i].offset = xstate_offsets[i];
+ p->xstate.comp[i].xss = curr_xstate & XSTATE_XSAVES_ONLY;
+ p->xstate.comp[i].align = curr_xstate & xstate_align;
+ }
+}
+
+/*
+ * Misc adjustments to the policy. Mostly clobbering reserved fields and
+ * duplicating shared fields. Intentionally hidden fields are annotated.
+ */
+static void recalculate_misc(struct cpu_policy *p)
+{
+ p->basic.raw_fms &= 0x0fff0fff; /* Clobber Processor Type on Intel. */
+ p->basic.apic_id = 0; /* Dynamic. */
+
+ p->basic.raw[0x5] = EMPTY_LEAF; /* MONITOR not exposed to guests. */
+ p->basic.raw[0x6] = EMPTY_LEAF; /* Therm/Power not exposed to guests. */
+
+ p->basic.raw[0x8] = EMPTY_LEAF;
+
+ /* TODO: Rework topology logic. */
+ memset(p->topo.raw, 0, sizeof(p->topo.raw));
+
+ p->basic.raw[0xc] = EMPTY_LEAF;
+
+ p->extd.e1d &= ~CPUID_COMMON_1D_FEATURES;
+
+ /* Most of Power/RAS hidden from guests. */
+ p->extd.raw[0x7].a = p->extd.raw[0x7].b = p->extd.raw[0x7].c = 0;
+
+ p->extd.raw[0x8].d = 0;
+
+ switch ( p->x86_vendor )
+ {
+ case X86_VENDOR_INTEL:
+ p->basic.l2_nr_queries = 1; /* Fixed to 1 query. */
+ p->basic.raw[0x3] = EMPTY_LEAF; /* PSN - always hidden. */
+ p->basic.raw[0x9] = EMPTY_LEAF; /* DCA - always hidden. */
+
+ p->extd.vendor_ebx = 0;
+ p->extd.vendor_ecx = 0;
+ p->extd.vendor_edx = 0;
+
+ p->extd.raw[0x1].a = p->extd.raw[0x1].b = 0;
+
+ p->extd.raw[0x5] = EMPTY_LEAF;
+ p->extd.raw[0x6].a = p->extd.raw[0x6].b = p->extd.raw[0x6].d = 0;
+
+ p->extd.raw[0x8].a &= 0x0000ffff;
+ p->extd.raw[0x8].c = 0;
+ break;
+
+ case X86_VENDOR_AMD:
+ case X86_VENDOR_HYGON:
+ zero_leaves(p->basic.raw, 0x2, 0x3);
+ memset(p->cache.raw, 0, sizeof(p->cache.raw));
+ zero_leaves(p->basic.raw, 0x9, 0xa);
+
+ p->extd.vendor_ebx = p->basic.vendor_ebx;
+ p->extd.vendor_ecx = p->basic.vendor_ecx;
+ p->extd.vendor_edx = p->basic.vendor_edx;
+
+ p->extd.raw_fms = p->basic.raw_fms;
+ p->extd.raw[0x1].b &= 0xff00ffff;
+ p->extd.e1d |= p->basic._1d & CPUID_COMMON_1D_FEATURES;
+
+ p->extd.raw[0x8].a &= 0x0000ffff; /* GuestMaxPhysAddr hidden. */
+ p->extd.raw[0x8].c &= 0x0003f0ff;
+
+ p->extd.raw[0x9] = EMPTY_LEAF;
+
+ zero_leaves(p->extd.raw, 0xb, 0x18);
+
+ /* 0x19 - TLB details. Pass through. */
+ /* 0x1a - Perf hints. Pass through. */
+
+ p->extd.raw[0x1b] = EMPTY_LEAF; /* IBS - not supported. */
+ p->extd.raw[0x1c] = EMPTY_LEAF; /* LWP - not supported. */
+ p->extd.raw[0x1d] = EMPTY_LEAF; /* TopoExt Cache */
+ p->extd.raw[0x1e] = EMPTY_LEAF; /* TopoExt APIC ID/Core/Node */
+ p->extd.raw[0x1f] = EMPTY_LEAF; /* SEV */
+ p->extd.raw[0x20] = EMPTY_LEAF; /* Platform QoS */
+ break;
+ }
+}
+
static void __init calculate_raw_policy(void)
{
struct cpu_policy *p = &raw_cpu_policy;
+ x86_cpuid_policy_fill_native(p);
+
+ /* Nothing good will come from Xen and libx86 disagreeing on vendor. */
+ ASSERT(p->x86_vendor == boot_cpu_data.x86_vendor);
+
/* 0x000000ce MSR_INTEL_PLATFORM_INFO */
/* Was already added by probe_cpuid_faulting() */
@@ -34,9 +362,50 @@ static void __init calculate_raw_policy(void)
static void __init calculate_host_policy(void)
{
struct cpu_policy *p = &host_cpu_policy;
+ unsigned int max_extd_leaf;
*p = raw_cpu_policy;
+ p->basic.max_leaf =
+ min_t(uint32_t, p->basic.max_leaf, ARRAY_SIZE(p->basic.raw) - 1);
+ p->feat.max_subleaf =
+ min_t(uint32_t, p->feat.max_subleaf, ARRAY_SIZE(p->feat.raw) - 1);
+
+ max_extd_leaf = p->extd.max_leaf;
+
+ /*
+ * For AMD/Hygon hardware before Zen3, we unilaterally modify LFENCE to be
+ * dispatch serialising for Spectre mitigations. Extend max_extd_leaf
+ * beyond what hardware supports, to include the feature leaf containing
+ * this information.
+ */
+ if ( cpu_has_lfence_dispatch )
+ max_extd_leaf = max(max_extd_leaf, 0x80000021);
+
+ p->extd.max_leaf = 0x80000000 | min_t(uint32_t, max_extd_leaf & 0xffff,
+ ARRAY_SIZE(p->extd.raw) - 1);
+
+ x86_cpu_featureset_to_policy(boot_cpu_data.x86_capability, p);
+ recalculate_xstate(p);
+ recalculate_misc(p);
+
+ /* When vPMU is disabled, drop it from the host policy. */
+ if ( vpmu_mode == XENPMU_MODE_OFF )
+ p->basic.raw[0xa] = EMPTY_LEAF;
+
+ if ( p->extd.svm )
+ {
+ /* Clamp to implemented features which require hardware support. */
+ p->extd.raw[0xa].d &= ((1u << SVM_FEATURE_NPT) |
+ (1u << SVM_FEATURE_LBRV) |
+ (1u << SVM_FEATURE_NRIPS) |
+ (1u << SVM_FEATURE_PAUSEFILTER) |
+ (1u << SVM_FEATURE_DECODEASSISTS));
+ /* Enable features which are always emulated. */
+ p->extd.raw[0xa].d |= ((1u << SVM_FEATURE_VMCBCLEAN) |
+ (1u << SVM_FEATURE_TSCRATEMSR));
+ }
+
/* 0x000000ce MSR_INTEL_PLATFORM_INFO */
/* probe_cpuid_faulting() sanity checks presence of MISC_FEATURES_ENABLES
*/
p->platform_info.cpuid_faulting = cpu_has_cpuid_faulting;
@@ -51,11 +420,88 @@ static void __init calculate_host_policy(void)
ARCH_CAPS_PBRSB_NO);
}
+static void __init guest_common_default_feature_adjustments(uint32_t *fs)
+{
+ /*
+ * IvyBridge client parts suffer from leakage of RDRAND data due to SRBDS
+ * (XSA-320 / CVE-2020-0543), and won't be receiving microcode to
+ * compensate.
+ *
+ * Mitigate by hiding RDRAND from guests by default, unless explicitly
+ * overridden on the Xen command line (cpuid=rdrand). Irrespective of the
+ * default setting, guests can use RDRAND if explicitly enabled
+ * (cpuid="host,rdrand=1") in the VM's config file, and VMs which were
+ * previously using RDRAND can migrate in.
+ */
+ if ( boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+ boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model == 0x3a &&
+ cpu_has_rdrand && !is_forced_cpu_cap(X86_FEATURE_RDRAND) )
+ __clear_bit(X86_FEATURE_RDRAND, fs);
+
+ /*
+ * On certain hardware, speculative or errata workarounds can result in
+ * TSX being placed in "force-abort" mode, where it doesn't actually
+ * function as expected, but is technically compatible with the ISA.
+ *
+ * Do not advertise RTM to guests by default if it won't actually work.
+ */
+ if ( rtm_disabled )
+ __clear_bit(X86_FEATURE_RTM, fs);
+}
+
+static void __init guest_common_feature_adjustments(uint32_t *fs)
+{
+ /* Unconditionally claim to be able to set the hypervisor bit. */
+ __set_bit(X86_FEATURE_HYPERVISOR, fs);
+
+ /*
+ * If IBRS is offered to the guest, unconditionally offer STIBP. It is a
+ * nop on non-HT hardware, and has this behaviour to make heterogeneous
+ * setups easier to manage.
+ */
+ if ( test_bit(X86_FEATURE_IBRSB, fs) )
+ __set_bit(X86_FEATURE_STIBP, fs);
+ if ( test_bit(X86_FEATURE_IBRS, fs) )
+ __set_bit(X86_FEATURE_AMD_STIBP, fs);
+
+ /*
+ * On hardware which supports IBRS/IBPB, we can offer IBPB independently
+ * of IBRS by using the AMD feature bit. An administrator may wish for
+ * performance reasons to offer IBPB without IBRS.
+ */
+ if ( host_cpu_policy.feat.ibrsb )
+ __set_bit(X86_FEATURE_IBPB, fs);
+}
+
static void __init calculate_pv_max_policy(void)
{
struct cpu_policy *p = &pv_max_cpu_policy;
+ uint32_t fs[FSCAPINTS];
+ unsigned int i;
*p = host_cpu_policy;
+ x86_cpu_policy_to_featureset(p, fs);
+
+ for ( i = 0; i < ARRAY_SIZE(fs); ++i )
+ fs[i] &= pv_max_featuremask[i];
+
+ /*
+ * If Xen isn't virtualising MSR_SPEC_CTRL for PV guests (functional
+ * availability, or admin choice), hide the feature.
+ */
+ if ( !boot_cpu_has(X86_FEATURE_SC_MSR_PV) )
+ {
+ __clear_bit(X86_FEATURE_IBRSB, fs);
+ __clear_bit(X86_FEATURE_IBRS, fs);
+ }
+
+ guest_common_feature_adjustments(fs);
+
+ sanitise_featureset(fs);
+ x86_cpu_featureset_to_policy(fs, p);
+ recalculate_xstate(p);
+
+ p->extd.raw[0xa] = EMPTY_LEAF; /* No SVM for PV guests. */
p->arch_caps.raw = 0; /* Not supported yet. */
}
@@ -63,15 +509,112 @@ static void __init calculate_pv_max_policy(void)
static void __init calculate_pv_def_policy(void)
{
struct cpu_policy *p = &pv_def_cpu_policy;
+ uint32_t fs[FSCAPINTS];
+ unsigned int i;
*p = pv_max_cpu_policy;
+ x86_cpu_policy_to_featureset(p, fs);
+
+ for ( i = 0; i < ARRAY_SIZE(fs); ++i )
+ fs[i] &= pv_def_featuremask[i];
+
+ guest_common_feature_adjustments(fs);
+ guest_common_default_feature_adjustments(fs);
+
+ sanitise_featureset(fs);
+ x86_cpu_featureset_to_policy(fs, p);
+ recalculate_xstate(p);
}
static void __init calculate_hvm_max_policy(void)
{
struct cpu_policy *p = &hvm_max_cpu_policy;
+ uint32_t fs[FSCAPINTS];
+ unsigned int i;
+ const uint32_t *mask;
*p = host_cpu_policy;
+ x86_cpu_policy_to_featureset(p, fs);
+
+ mask = hvm_hap_supported() ?
+ hvm_hap_max_featuremask : hvm_shadow_max_featuremask;
+
+ for ( i = 0; i < ARRAY_SIZE(fs); ++i )
+ fs[i] &= mask[i];
+
+ /*
+ * Xen can provide an (x2)APIC emulation to HVM guests even if the host's
+ * (x2)APIC isn't enabled.
+ */
+ __set_bit(X86_FEATURE_APIC, fs);
+ __set_bit(X86_FEATURE_X2APIC, fs);
+
+ /*
+ * We don't support EFER.LMSLE at all. AMD has dropped the feature from
+ * hardware and allocated a CPUID bit to indicate its absence.
+ */
+ __set_bit(X86_FEATURE_NO_LMSL, fs);
+
+ /*
+ * On AMD, PV guests are entirely unable to use SYSENTER as Xen runs in
+ * long mode (and init_amd() has cleared it out of host capabilities), but
+ * HVM guests are able if running in protected mode.
+ */
+ if ( (boot_cpu_data.x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON)) &&
+ raw_cpu_policy.basic.sep )
+ __set_bit(X86_FEATURE_SEP, fs);
+
+ /*
+ * VIRT_SSBD is exposed in the default policy as a result of
+ * amd_virt_spec_ctrl being set, it also needs exposing in the max policy.
+ */
+ if ( amd_virt_spec_ctrl )
+ __set_bit(X86_FEATURE_VIRT_SSBD, fs);
+
+ /*
+ * If Xen isn't virtualising MSR_SPEC_CTRL for HVM guests (functional
+ * availability, or admin choice), hide the feature.
+ */
+ if ( !boot_cpu_has(X86_FEATURE_SC_MSR_HVM) )
+ {
+ __clear_bit(X86_FEATURE_IBRSB, fs);
+ __clear_bit(X86_FEATURE_IBRS, fs);
+ }
+ else if ( boot_cpu_has(X86_FEATURE_AMD_SSBD) )
+ /*
+ * If SPEC_CTRL.SSBD is available VIRT_SPEC_CTRL.SSBD can be exposed
+ * and implemented using the former. Expose in the max policy only as
+ * the preference is for guests to use SPEC_CTRL.SSBD if available.
+ */
+ __set_bit(X86_FEATURE_VIRT_SSBD, fs);
+
+ /*
+ * With VT-x, some features are only supported by Xen if dedicated
+ * hardware support is also available.
+ */
+ if ( cpu_has_vmx )
+ {
+ if ( !cpu_has_vmx_mpx )
+ __clear_bit(X86_FEATURE_MPX, fs);
+
+ if ( !cpu_has_vmx_xsaves )
+ __clear_bit(X86_FEATURE_XSAVES, fs);
+ }
+
+ /*
+ * Xen doesn't use PKS, so the guest support for it has opted to not use
+ * the VMCS load/save controls for efficiency reasons. This depends on
+ * the exact vmentry/exit behaviour, so don't expose PKS in other
+ * situations until someone has cross-checked the behaviour for safety.
+ */
+ if ( !cpu_has_vmx )
+ __clear_bit(X86_FEATURE_PKS, fs);
+
+ guest_common_feature_adjustments(fs);
+
+ sanitise_featureset(fs);
+ x86_cpu_featureset_to_policy(fs, p);
+ recalculate_xstate(p);
/* It's always possible to emulate CPUID faulting for HVM guests */
p->platform_info.cpuid_faulting = true;
@@ -82,8 +625,32 @@ static void __init calculate_hvm_max_policy(void)
static void __init calculate_hvm_def_policy(void)
{
struct cpu_policy *p = &hvm_def_cpu_policy;
+ uint32_t fs[FSCAPINTS];
+ unsigned int i;
+ const uint32_t *mask;
*p = hvm_max_cpu_policy;
+ x86_cpu_policy_to_featureset(p, fs);
+
+ mask = hvm_hap_supported() ?
+ hvm_hap_def_featuremask : hvm_shadow_def_featuremask;
+
+ for ( i = 0; i < ARRAY_SIZE(fs); ++i )
+ fs[i] &= mask[i];
+
+ guest_common_feature_adjustments(fs);
+ guest_common_default_feature_adjustments(fs);
+
+ /*
+ * Only expose VIRT_SSBD if AMD_SSBD is not available, and thus
+ * amd_virt_spec_ctrl is set.
+ */
+ if ( amd_virt_spec_ctrl )
+ __set_bit(X86_FEATURE_VIRT_SSBD, fs);
+
+ sanitise_featureset(fs);
+ x86_cpu_featureset_to_policy(fs, p);
+ recalculate_xstate(p);
}
void __init init_guest_cpu_policies(void)
@@ -149,3 +716,188 @@ int init_domain_cpu_policy(struct domain *d)
return 0;
}
+
+void recalculate_cpuid_policy(struct domain *d)
+{
+ struct cpu_policy *p = d->arch.cpuid;
+ const struct cpu_policy *max = is_pv_domain(d)
+ ? (IS_ENABLED(CONFIG_PV) ? &pv_max_cpu_policy : NULL)
+ : (IS_ENABLED(CONFIG_HVM) ? &hvm_max_cpu_policy : NULL);
+ uint32_t fs[FSCAPINTS], max_fs[FSCAPINTS];
+ unsigned int i;
+
+ if ( !max )
+ {
+ ASSERT_UNREACHABLE();
+ return;
+ }
+
+ p->x86_vendor = x86_cpuid_lookup_vendor(
+ p->basic.vendor_ebx, p->basic.vendor_ecx, p->basic.vendor_edx);
+
+ p->basic.max_leaf = min(p->basic.max_leaf, max->basic.max_leaf);
+ p->feat.max_subleaf = min(p->feat.max_subleaf, max->feat.max_subleaf);
+ p->extd.max_leaf = 0x80000000 | min(p->extd.max_leaf & 0xffff,
+ ((p->x86_vendor & (X86_VENDOR_AMD |
+
X86_VENDOR_HYGON))
+ ? CPUID_GUEST_NR_EXTD_AMD
+ : CPUID_GUEST_NR_EXTD_INTEL) - 1);
+
+ x86_cpu_policy_to_featureset(p, fs);
+ x86_cpu_policy_to_featureset(max, max_fs);
+
+ if ( is_hvm_domain(d) )
+ {
+ /*
+ * HVM domains using Shadow paging have further restrictions on their
+ * available paging features.
+ */
+ if ( !hap_enabled(d) )
+ {
+ for ( i = 0; i < ARRAY_SIZE(max_fs); i++ )
+ max_fs[i] &= hvm_shadow_max_featuremask[i];
+ }
+
+ /* Hide nested-virt if it hasn't been explicitly configured. */
+ if ( !nestedhvm_enabled(d) )
+ {
+ __clear_bit(X86_FEATURE_VMX, max_fs);
+ __clear_bit(X86_FEATURE_SVM, max_fs);
+ }
+ }
+
+ /*
+ * Allow the toolstack to set HTT, X2APIC and CMP_LEGACY. These bits
+ * affect how to interpret topology information in other cpuid leaves.
+ */
+ __set_bit(X86_FEATURE_HTT, max_fs);
+ __set_bit(X86_FEATURE_X2APIC, max_fs);
+ __set_bit(X86_FEATURE_CMP_LEGACY, max_fs);
+
+ /*
+ * 32bit PV domains can't use any Long Mode features, and cannot use
+ * SYSCALL on non-AMD hardware.
+ */
+ if ( is_pv_32bit_domain(d) )
+ {
+ __clear_bit(X86_FEATURE_LM, max_fs);
+ if ( !(boot_cpu_data.x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON))
)
+ __clear_bit(X86_FEATURE_SYSCALL, max_fs);
+ }
+
+ /* Clamp the toolstacks choices to reality. */
+ for ( i = 0; i < ARRAY_SIZE(fs); i++ )
+ fs[i] &= max_fs[i];
+
+ if ( p->basic.max_leaf < XSTATE_CPUID )
+ __clear_bit(X86_FEATURE_XSAVE, fs);
+
+ sanitise_featureset(fs);
+
+ /* Fold host's FDP_EXCP_ONLY and NO_FPU_SEL into guest's view. */
+ fs[FEATURESET_7b0] &= ~(cpufeat_mask(X86_FEATURE_FDP_EXCP_ONLY) |
+ cpufeat_mask(X86_FEATURE_NO_FPU_SEL));
+ fs[FEATURESET_7b0] |= (host_cpu_policy.feat._7b0 &
+ (cpufeat_mask(X86_FEATURE_FDP_EXCP_ONLY) |
+ cpufeat_mask(X86_FEATURE_NO_FPU_SEL)));
+
+ x86_cpu_featureset_to_policy(fs, p);
+
+ /* Pass host cacheline size through to guests. */
+ p->basic.clflush_size = max->basic.clflush_size;
+
+ p->extd.maxphysaddr = min(p->extd.maxphysaddr, max->extd.maxphysaddr);
+ p->extd.maxphysaddr = min_t(uint8_t, p->extd.maxphysaddr,
+ paging_max_paddr_bits(d));
+ p->extd.maxphysaddr = max_t(uint8_t, p->extd.maxphysaddr,
+ (p->basic.pae || p->basic.pse36) ? 36 : 32);
+
+ p->extd.maxlinaddr = p->extd.lm ? 48 : 32;
+
+ recalculate_xstate(p);
+ recalculate_misc(p);
+
+ for ( i = 0; i < ARRAY_SIZE(p->cache.raw); ++i )
+ {
+ if ( p->cache.subleaf[i].type >= 1 &&
+ p->cache.subleaf[i].type <= 3 )
+ {
+ /* Subleaf has a valid cache type. Zero reserved fields. */
+ p->cache.raw[i].a &= 0xffffc3ffu;
+ p->cache.raw[i].d &= 0x00000007u;
+ }
+ else
+ {
+ /* Subleaf is not valid. Zero the rest of the union. */
+ zero_leaves(p->cache.raw, i, ARRAY_SIZE(p->cache.raw) - 1);
+ break;
+ }
+ }
+
+ if ( vpmu_mode == XENPMU_MODE_OFF ||
+ ((vpmu_mode & XENPMU_MODE_ALL) && !is_hardware_domain(d)) )
+ p->basic.raw[0xa] = EMPTY_LEAF;
+
+ if ( !p->extd.svm )
+ p->extd.raw[0xa] = EMPTY_LEAF;
+
+ if ( !p->extd.page1gb )
+ p->extd.raw[0x19] = EMPTY_LEAF;
+}
+
+void __init init_dom0_cpuid_policy(struct domain *d)
+{
+ struct cpu_policy *p = d->arch.cpuid;
+
+ /* dom0 can't migrate. Give it ITSC if available. */
+ if ( cpu_has_itsc )
+ p->extd.itsc = true;
+
+ /*
+ * Expose the "hardware speculation behaviour" bits of ARCH_CAPS to dom0,
+ * so dom0 can turn off workarounds as appropriate. Temporary, until the
+ * domain policy logic gains a better understanding of MSRs.
+ */
+ if ( cpu_has_arch_caps )
+ p->feat.arch_caps = true;
+
+ /* Apply dom0-cpuid= command line settings, if provided. */
+ if ( dom0_cpuid_cmdline )
+ {
+ uint32_t fs[FSCAPINTS];
+ unsigned int i;
+
+ x86_cpu_policy_to_featureset(p, fs);
+
+ for ( i = 0; i < ARRAY_SIZE(fs); ++i )
+ {
+ fs[i] |= dom0_enable_feat [i];
+ fs[i] &= ~dom0_disable_feat[i];
+ }
+
+ x86_cpu_featureset_to_policy(fs, p);
+
+ recalculate_cpuid_policy(d);
+ }
+}
+
+static void __init __maybe_unused build_assertions(void)
+{
+ BUILD_BUG_ON(ARRAY_SIZE(known_features) != FSCAPINTS);
+ BUILD_BUG_ON(ARRAY_SIZE(pv_max_featuremask) != FSCAPINTS);
+ BUILD_BUG_ON(ARRAY_SIZE(hvm_shadow_max_featuremask) != FSCAPINTS);
+ BUILD_BUG_ON(ARRAY_SIZE(hvm_hap_max_featuremask) != FSCAPINTS);
+ BUILD_BUG_ON(ARRAY_SIZE(deep_features) != FSCAPINTS);
+
+ /* Find some more clever allocation scheme if this trips. */
+ BUILD_BUG_ON(sizeof(struct cpu_policy) > PAGE_SIZE);
+
+ BUILD_BUG_ON(sizeof(raw_cpu_policy.basic) !=
+ sizeof(raw_cpu_policy.basic.raw));
+ BUILD_BUG_ON(sizeof(raw_cpu_policy.feat) !=
+ sizeof(raw_cpu_policy.feat.raw));
+ BUILD_BUG_ON(sizeof(raw_cpu_policy.xstate) !=
+ sizeof(raw_cpu_policy.xstate.raw));
+ BUILD_BUG_ON(sizeof(raw_cpu_policy.extd) !=
+ sizeof(raw_cpu_policy.extd.raw));
+}
diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
index 5eb5f18935..3f20c342fd 100644
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -1,638 +1,14 @@
-#include <xen/init.h>
-#include <xen/lib.h>
-#include <xen/param.h>
#include <xen/sched.h>
-#include <xen/nospec.h>
-#include <asm/amd.h>
+#include <xen/types.h>
+
+#include <public/hvm/params.h>
+
#include <asm/cpu-policy.h>
#include <asm/cpuid.h>
-#include <asm/hvm/hvm.h>
-#include <asm/hvm/nestedhvm.h>
-#include <asm/hvm/svm/svm.h>
#include <asm/hvm/viridian.h>
-#include <asm/hvm/vmx/vmcs.h>
-#include <asm/paging.h>
-#include <asm/processor.h>
#include <asm/xstate.h>
-const uint32_t known_features[] = INIT_KNOWN_FEATURES;
-
-static const uint32_t __initconst pv_max_featuremask[] = INIT_PV_MAX_FEATURES;
-static const uint32_t hvm_shadow_max_featuremask[] =
INIT_HVM_SHADOW_MAX_FEATURES;
-static const uint32_t __initconst hvm_hap_max_featuremask[] =
- INIT_HVM_HAP_MAX_FEATURES;
-static const uint32_t __initconst pv_def_featuremask[] = INIT_PV_DEF_FEATURES;
-static const uint32_t __initconst hvm_shadow_def_featuremask[] =
- INIT_HVM_SHADOW_DEF_FEATURES;
-static const uint32_t __initconst hvm_hap_def_featuremask[] =
- INIT_HVM_HAP_DEF_FEATURES;
-static const uint32_t deep_features[] = INIT_DEEP_FEATURES;
-
-static const struct feature_name {
- const char *name;
- unsigned int bit;
-} feature_names[] __initconstrel = INIT_FEATURE_NAMES;
-
-/*
- * Parse a list of cpuid feature names -> bool, calling the callback for any
- * matches found.
- *
- * always_inline, because this is init code only and we really don't want a
- * function pointer call in the middle of the loop.
- */
-static int __init always_inline parse_cpuid(
- const char *s, void (*callback)(unsigned int feat, bool val))
-{
- const char *ss;
- int val, rc = 0;
-
- do {
- const struct feature_name *lhs, *rhs, *mid = NULL /* GCC... */;
- const char *feat;
-
- ss = strchr(s, ',');
- if ( !ss )
- ss = strchr(s, '\0');
-
- /* Skip the 'no-' prefix for name comparisons. */
- feat = s;
- if ( strncmp(s, "no-", 3) == 0 )
- feat += 3;
-
- /* (Re)initalise lhs and rhs for binary search. */
- lhs = feature_names;
- rhs = feature_names + ARRAY_SIZE(feature_names);
-
- while ( lhs < rhs )
- {
- int res;
-
- mid = lhs + (rhs - lhs) / 2;
- res = cmdline_strcmp(feat, mid->name);
-
- if ( res < 0 )
- {
- rhs = mid;
- continue;
- }
- if ( res > 0 )
- {
- lhs = mid + 1;
- continue;
- }
-
- if ( (val = parse_boolean(mid->name, s, ss)) >= 0 )
- {
- callback(mid->bit, val);
- mid = NULL;
- }
-
- break;
- }
-
- /*
- * Mid being NULL means that the name and boolean were successfully
- * identified. Everything else is an error.
- */
- if ( mid )
- rc = -EINVAL;
-
- s = ss + 1;
- } while ( *ss );
-
- return rc;
-}
-
-static void __init cf_check _parse_xen_cpuid(unsigned int feat, bool val)
-{
- if ( !val )
- setup_clear_cpu_cap(feat);
- else if ( feat == X86_FEATURE_RDRAND &&
- (cpuid_ecx(1) & cpufeat_mask(X86_FEATURE_RDRAND)) )
- setup_force_cpu_cap(X86_FEATURE_RDRAND);
-}
-
-static int __init cf_check parse_xen_cpuid(const char *s)
-{
- return parse_cpuid(s, _parse_xen_cpuid);
-}
-custom_param("cpuid", parse_xen_cpuid);
-
-static bool __initdata dom0_cpuid_cmdline;
-static uint32_t __initdata dom0_enable_feat[FSCAPINTS];
-static uint32_t __initdata dom0_disable_feat[FSCAPINTS];
-
-static void __init cf_check _parse_dom0_cpuid(unsigned int feat, bool val)
-{
- __set_bit (feat, val ? dom0_enable_feat : dom0_disable_feat);
- __clear_bit(feat, val ? dom0_disable_feat : dom0_enable_feat );
-}
-
-static int __init cf_check parse_dom0_cpuid(const char *s)
-{
- dom0_cpuid_cmdline = true;
-
- return parse_cpuid(s, _parse_dom0_cpuid);
-}
-custom_param("dom0-cpuid", parse_dom0_cpuid);
-
#define EMPTY_LEAF ((struct cpuid_leaf){})
-static void zero_leaves(struct cpuid_leaf *l,
- unsigned int first, unsigned int last)
-{
- memset(&l[first], 0, sizeof(*l) * (last - first + 1));
-}
-
-static void sanitise_featureset(uint32_t *fs)
-{
- /* for_each_set_bit() uses unsigned longs. Extend with zeroes. */
- uint32_t disabled_features[
- ROUNDUP(FSCAPINTS, sizeof(unsigned long)/sizeof(uint32_t))] = {};
- unsigned int i;
-
- for ( i = 0; i < FSCAPINTS; ++i )
- {
- /* Clamp to known mask. */
- fs[i] &= known_features[i];
-
- /*
- * Identify which features with deep dependencies have been
- * disabled.
- */
- disabled_features[i] = ~fs[i] & deep_features[i];
- }
-
- for_each_set_bit(i, (void *)disabled_features,
- sizeof(disabled_features) * 8)
- {
- const uint32_t *dfs = x86_cpuid_lookup_deep_deps(i);
- unsigned int j;
-
- ASSERT(dfs); /* deep_features[] should guarentee this. */
-
- for ( j = 0; j < FSCAPINTS; ++j )
- {
- fs[j] &= ~dfs[j];
- disabled_features[j] &= ~dfs[j];
- }
- }
-}
-
-static void recalculate_xstate(struct cpuid_policy *p)
-{
- uint64_t xstates = XSTATE_FP_SSE;
- uint32_t xstate_size = XSTATE_AREA_MIN_SIZE;
- unsigned int i, Da1 = p->xstate.Da1;
-
- /*
- * The Da1 leaf is the only piece of information preserved in the common
- * case. Everything else is derived from other feature state.
- */
- memset(&p->xstate, 0, sizeof(p->xstate));
-
- if ( !p->basic.xsave )
- return;
-
- if ( p->basic.avx )
- {
- xstates |= X86_XCR0_YMM;
- xstate_size = max(xstate_size,
- xstate_offsets[X86_XCR0_YMM_POS] +
- xstate_sizes[X86_XCR0_YMM_POS]);
- }
-
- if ( p->feat.mpx )
- {
- xstates |= X86_XCR0_BNDREGS | X86_XCR0_BNDCSR;
- xstate_size = max(xstate_size,
- xstate_offsets[X86_XCR0_BNDCSR_POS] +
- xstate_sizes[X86_XCR0_BNDCSR_POS]);
- }
-
- if ( p->feat.avx512f )
- {
- xstates |= X86_XCR0_OPMASK | X86_XCR0_ZMM | X86_XCR0_HI_ZMM;
- xstate_size = max(xstate_size,
- xstate_offsets[X86_XCR0_HI_ZMM_POS] +
- xstate_sizes[X86_XCR0_HI_ZMM_POS]);
- }
-
- if ( p->feat.pku )
- {
- xstates |= X86_XCR0_PKRU;
- xstate_size = max(xstate_size,
- xstate_offsets[X86_XCR0_PKRU_POS] +
- xstate_sizes[X86_XCR0_PKRU_POS]);
- }
-
- p->xstate.max_size = xstate_size;
- p->xstate.xcr0_low = xstates & ~XSTATE_XSAVES_ONLY;
- p->xstate.xcr0_high = (xstates & ~XSTATE_XSAVES_ONLY) >> 32;
-
- p->xstate.Da1 = Da1;
- if ( p->xstate.xsaves )
- {
- p->xstate.xss_low = xstates & XSTATE_XSAVES_ONLY;
- p->xstate.xss_high = (xstates & XSTATE_XSAVES_ONLY) >> 32;
- }
- else
- xstates &= ~XSTATE_XSAVES_ONLY;
-
- for ( i = 2; i < min(63ul, ARRAY_SIZE(p->xstate.comp)); ++i )
- {
- uint64_t curr_xstate = 1ul << i;
-
- if ( !(xstates & curr_xstate) )
- continue;
-
- p->xstate.comp[i].size = xstate_sizes[i];
- p->xstate.comp[i].offset = xstate_offsets[i];
- p->xstate.comp[i].xss = curr_xstate & XSTATE_XSAVES_ONLY;
- p->xstate.comp[i].align = curr_xstate & xstate_align;
- }
-}
-
-/*
- * Misc adjustments to the policy. Mostly clobbering reserved fields and
- * duplicating shared fields. Intentionally hidden fields are annotated.
- */
-static void recalculate_misc(struct cpuid_policy *p)
-{
- p->basic.raw_fms &= 0x0fff0fff; /* Clobber Processor Type on Intel. */
- p->basic.apic_id = 0; /* Dynamic. */
-
- p->basic.raw[0x5] = EMPTY_LEAF; /* MONITOR not exposed to guests. */
- p->basic.raw[0x6] = EMPTY_LEAF; /* Therm/Power not exposed to guests. */
-
- p->basic.raw[0x8] = EMPTY_LEAF;
-
- /* TODO: Rework topology logic. */
- memset(p->topo.raw, 0, sizeof(p->topo.raw));
-
- p->basic.raw[0xc] = EMPTY_LEAF;
-
- p->extd.e1d &= ~CPUID_COMMON_1D_FEATURES;
-
- /* Most of Power/RAS hidden from guests. */
- p->extd.raw[0x7].a = p->extd.raw[0x7].b = p->extd.raw[0x7].c = 0;
-
- p->extd.raw[0x8].d = 0;
-
- switch ( p->x86_vendor )
- {
- case X86_VENDOR_INTEL:
- p->basic.l2_nr_queries = 1; /* Fixed to 1 query. */
- p->basic.raw[0x3] = EMPTY_LEAF; /* PSN - always hidden. */
- p->basic.raw[0x9] = EMPTY_LEAF; /* DCA - always hidden. */
-
- p->extd.vendor_ebx = 0;
- p->extd.vendor_ecx = 0;
- p->extd.vendor_edx = 0;
-
- p->extd.raw[0x1].a = p->extd.raw[0x1].b = 0;
-
- p->extd.raw[0x5] = EMPTY_LEAF;
- p->extd.raw[0x6].a = p->extd.raw[0x6].b = p->extd.raw[0x6].d = 0;
-
- p->extd.raw[0x8].a &= 0x0000ffff;
- p->extd.raw[0x8].c = 0;
- break;
-
- case X86_VENDOR_AMD:
- case X86_VENDOR_HYGON:
- zero_leaves(p->basic.raw, 0x2, 0x3);
- memset(p->cache.raw, 0, sizeof(p->cache.raw));
- zero_leaves(p->basic.raw, 0x9, 0xa);
-
- p->extd.vendor_ebx = p->basic.vendor_ebx;
- p->extd.vendor_ecx = p->basic.vendor_ecx;
- p->extd.vendor_edx = p->basic.vendor_edx;
-
- p->extd.raw_fms = p->basic.raw_fms;
- p->extd.raw[0x1].b &= 0xff00ffff;
- p->extd.e1d |= p->basic._1d & CPUID_COMMON_1D_FEATURES;
-
- p->extd.raw[0x8].a &= 0x0000ffff; /* GuestMaxPhysAddr hidden. */
- p->extd.raw[0x8].c &= 0x0003f0ff;
-
- p->extd.raw[0x9] = EMPTY_LEAF;
-
- zero_leaves(p->extd.raw, 0xb, 0x18);
-
- /* 0x19 - TLB details. Pass through. */
- /* 0x1a - Perf hints. Pass through. */
-
- p->extd.raw[0x1b] = EMPTY_LEAF; /* IBS - not supported. */
- p->extd.raw[0x1c] = EMPTY_LEAF; /* LWP - not supported. */
- p->extd.raw[0x1d] = EMPTY_LEAF; /* TopoExt Cache */
- p->extd.raw[0x1e] = EMPTY_LEAF; /* TopoExt APIC ID/Core/Node */
- p->extd.raw[0x1f] = EMPTY_LEAF; /* SEV */
- p->extd.raw[0x20] = EMPTY_LEAF; /* Platform QoS */
- break;
- }
-}
-
-static void __init calculate_raw_policy(void)
-{
- struct cpuid_policy *p = &raw_cpu_policy;
-
- x86_cpuid_policy_fill_native(p);
-
- /* Nothing good will come from Xen and libx86 disagreeing on vendor. */
- ASSERT(p->x86_vendor == boot_cpu_data.x86_vendor);
-}
-
-static void __init calculate_host_policy(void)
-{
- struct cpuid_policy *p = &host_cpu_policy;
- unsigned int max_extd_leaf;
-
- *p = raw_cpu_policy;
-
- p->basic.max_leaf =
- min_t(uint32_t, p->basic.max_leaf, ARRAY_SIZE(p->basic.raw) - 1);
- p->feat.max_subleaf =
- min_t(uint32_t, p->feat.max_subleaf, ARRAY_SIZE(p->feat.raw) - 1);
-
- max_extd_leaf = p->extd.max_leaf;
-
- /*
- * For AMD/Hygon hardware before Zen3, we unilaterally modify LFENCE to be
- * dispatch serialising for Spectre mitigations. Extend max_extd_leaf
- * beyond what hardware supports, to include the feature leaf containing
- * this information.
- */
- if ( cpu_has_lfence_dispatch )
- max_extd_leaf = max(max_extd_leaf, 0x80000021);
-
- p->extd.max_leaf = 0x80000000 | min_t(uint32_t, max_extd_leaf & 0xffff,
- ARRAY_SIZE(p->extd.raw) - 1);
-
- x86_cpu_featureset_to_policy(boot_cpu_data.x86_capability, p);
- recalculate_xstate(p);
- recalculate_misc(p);
-
- /* When vPMU is disabled, drop it from the host policy. */
- if ( vpmu_mode == XENPMU_MODE_OFF )
- p->basic.raw[0xa] = EMPTY_LEAF;
-
- if ( p->extd.svm )
- {
- /* Clamp to implemented features which require hardware support. */
- p->extd.raw[0xa].d &= ((1u << SVM_FEATURE_NPT) |
- (1u << SVM_FEATURE_LBRV) |
- (1u << SVM_FEATURE_NRIPS) |
- (1u << SVM_FEATURE_PAUSEFILTER) |
- (1u << SVM_FEATURE_DECODEASSISTS));
- /* Enable features which are always emulated. */
- p->extd.raw[0xa].d |= ((1u << SVM_FEATURE_VMCBCLEAN) |
- (1u << SVM_FEATURE_TSCRATEMSR));
- }
-}
-
-static void __init guest_common_default_feature_adjustments(uint32_t *fs)
-{
- /*
- * IvyBridge client parts suffer from leakage of RDRAND data due to SRBDS
- * (XSA-320 / CVE-2020-0543), and won't be receiving microcode to
- * compensate.
- *
- * Mitigate by hiding RDRAND from guests by default, unless explicitly
- * overridden on the Xen command line (cpuid=rdrand). Irrespective of the
- * default setting, guests can use RDRAND if explicitly enabled
- * (cpuid="host,rdrand=1") in the VM's config file, and VMs which were
- * previously using RDRAND can migrate in.
- */
- if ( boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
- boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model == 0x3a &&
- cpu_has_rdrand && !is_forced_cpu_cap(X86_FEATURE_RDRAND) )
- __clear_bit(X86_FEATURE_RDRAND, fs);
-
- /*
- * On certain hardware, speculative or errata workarounds can result in
- * TSX being placed in "force-abort" mode, where it doesn't actually
- * function as expected, but is technically compatible with the ISA.
- *
- * Do not advertise RTM to guests by default if it won't actually work.
- */
- if ( rtm_disabled )
- __clear_bit(X86_FEATURE_RTM, fs);
-}
-
-static void __init guest_common_feature_adjustments(uint32_t *fs)
-{
- /* Unconditionally claim to be able to set the hypervisor bit. */
- __set_bit(X86_FEATURE_HYPERVISOR, fs);
-
- /*
- * If IBRS is offered to the guest, unconditionally offer STIBP. It is a
- * nop on non-HT hardware, and has this behaviour to make heterogeneous
- * setups easier to manage.
- */
- if ( test_bit(X86_FEATURE_IBRSB, fs) )
- __set_bit(X86_FEATURE_STIBP, fs);
- if ( test_bit(X86_FEATURE_IBRS, fs) )
- __set_bit(X86_FEATURE_AMD_STIBP, fs);
-
- /*
- * On hardware which supports IBRS/IBPB, we can offer IBPB independently
- * of IBRS by using the AMD feature bit. An administrator may wish for
- * performance reasons to offer IBPB without IBRS.
- */
- if ( host_cpu_policy.feat.ibrsb )
- __set_bit(X86_FEATURE_IBPB, fs);
-}
-
-static void __init calculate_pv_max_policy(void)
-{
- struct cpuid_policy *p = &pv_max_cpu_policy;
- uint32_t pv_featureset[FSCAPINTS];
- unsigned int i;
-
- *p = host_cpu_policy;
- x86_cpu_policy_to_featureset(p, pv_featureset);
-
- for ( i = 0; i < ARRAY_SIZE(pv_featureset); ++i )
- pv_featureset[i] &= pv_max_featuremask[i];
-
- /*
- * If Xen isn't virtualising MSR_SPEC_CTRL for PV guests (functional
- * availability, or admin choice), hide the feature.
- */
- if ( !boot_cpu_has(X86_FEATURE_SC_MSR_PV) )
- {
- __clear_bit(X86_FEATURE_IBRSB, pv_featureset);
- __clear_bit(X86_FEATURE_IBRS, pv_featureset);
- }
-
- guest_common_feature_adjustments(pv_featureset);
-
- sanitise_featureset(pv_featureset);
- x86_cpu_featureset_to_policy(pv_featureset, p);
- recalculate_xstate(p);
-
- p->extd.raw[0xa] = EMPTY_LEAF; /* No SVM for PV guests. */
-}
-
-static void __init calculate_pv_def_policy(void)
-{
- struct cpuid_policy *p = &pv_def_cpu_policy;
- uint32_t pv_featureset[FSCAPINTS];
- unsigned int i;
-
- *p = pv_max_cpu_policy;
- x86_cpu_policy_to_featureset(p, pv_featureset);
-
- for ( i = 0; i < ARRAY_SIZE(pv_featureset); ++i )
- pv_featureset[i] &= pv_def_featuremask[i];
-
- guest_common_feature_adjustments(pv_featureset);
- guest_common_default_feature_adjustments(pv_featureset);
-
- sanitise_featureset(pv_featureset);
- x86_cpu_featureset_to_policy(pv_featureset, p);
- recalculate_xstate(p);
-}
-
-static void __init calculate_hvm_max_policy(void)
-{
- struct cpuid_policy *p = &hvm_max_cpu_policy;
- uint32_t hvm_featureset[FSCAPINTS];
- unsigned int i;
- const uint32_t *hvm_featuremask;
-
- *p = host_cpu_policy;
- x86_cpu_policy_to_featureset(p, hvm_featureset);
-
- hvm_featuremask = hvm_hap_supported() ?
- hvm_hap_max_featuremask : hvm_shadow_max_featuremask;
-
- for ( i = 0; i < ARRAY_SIZE(hvm_featureset); ++i )
- hvm_featureset[i] &= hvm_featuremask[i];
-
- /*
- * Xen can provide an (x2)APIC emulation to HVM guests even if the host's
- * (x2)APIC isn't enabled.
- */
- __set_bit(X86_FEATURE_APIC, hvm_featureset);
- __set_bit(X86_FEATURE_X2APIC, hvm_featureset);
-
- /*
- * We don't support EFER.LMSLE at all. AMD has dropped the feature from
- * hardware and allocated a CPUID bit to indicate its absence.
- */
- __set_bit(X86_FEATURE_NO_LMSL, hvm_featureset);
-
- /*
- * On AMD, PV guests are entirely unable to use SYSENTER as Xen runs in
- * long mode (and init_amd() has cleared it out of host capabilities), but
- * HVM guests are able if running in protected mode.
- */
- if ( (boot_cpu_data.x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON)) &&
- raw_cpu_policy.basic.sep )
- __set_bit(X86_FEATURE_SEP, hvm_featureset);
-
- /*
- * VIRT_SSBD is exposed in the default policy as a result of
- * amd_virt_spec_ctrl being set, it also needs exposing in the max policy.
- */
- if ( amd_virt_spec_ctrl )
- __set_bit(X86_FEATURE_VIRT_SSBD, hvm_featureset);
-
- /*
- * If Xen isn't virtualising MSR_SPEC_CTRL for HVM guests (functional
- * availability, or admin choice), hide the feature.
- */
- if ( !boot_cpu_has(X86_FEATURE_SC_MSR_HVM) )
- {
- __clear_bit(X86_FEATURE_IBRSB, hvm_featureset);
- __clear_bit(X86_FEATURE_IBRS, hvm_featureset);
- }
- else if ( boot_cpu_has(X86_FEATURE_AMD_SSBD) )
- /*
- * If SPEC_CTRL.SSBD is available VIRT_SPEC_CTRL.SSBD can be exposed
- * and implemented using the former. Expose in the max policy only as
- * the preference is for guests to use SPEC_CTRL.SSBD if available.
- */
- __set_bit(X86_FEATURE_VIRT_SSBD, hvm_featureset);
-
- /*
- * With VT-x, some features are only supported by Xen if dedicated
- * hardware support is also available.
- */
- if ( cpu_has_vmx )
- {
- if ( !cpu_has_vmx_mpx )
- __clear_bit(X86_FEATURE_MPX, hvm_featureset);
-
- if ( !cpu_has_vmx_xsaves )
- __clear_bit(X86_FEATURE_XSAVES, hvm_featureset);
- }
-
- /*
- * Xen doesn't use PKS, so the guest support for it has opted to not use
- * the VMCS load/save controls for efficiency reasons. This depends on
- * the exact vmentry/exit behaviour, so don't expose PKS in other
- * situations until someone has cross-checked the behaviour for safety.
- */
- if ( !cpu_has_vmx )
- __clear_bit(X86_FEATURE_PKS, hvm_featureset);
-
- guest_common_feature_adjustments(hvm_featureset);
-
- sanitise_featureset(hvm_featureset);
- x86_cpu_featureset_to_policy(hvm_featureset, p);
- recalculate_xstate(p);
-}
-
-static void __init calculate_hvm_def_policy(void)
-{
- struct cpuid_policy *p = &hvm_def_cpu_policy;
- uint32_t hvm_featureset[FSCAPINTS];
- unsigned int i;
- const uint32_t *hvm_featuremask;
-
- *p = hvm_max_cpu_policy;
- x86_cpu_policy_to_featureset(p, hvm_featureset);
-
- hvm_featuremask = hvm_hap_supported() ?
- hvm_hap_def_featuremask : hvm_shadow_def_featuremask;
-
- for ( i = 0; i < ARRAY_SIZE(hvm_featureset); ++i )
- hvm_featureset[i] &= hvm_featuremask[i];
-
- guest_common_feature_adjustments(hvm_featureset);
- guest_common_default_feature_adjustments(hvm_featureset);
-
- /*
- * Only expose VIRT_SSBD if AMD_SSBD is not available, and thus
- * amd_virt_spec_ctrl is set.
- */
- if ( amd_virt_spec_ctrl )
- __set_bit(X86_FEATURE_VIRT_SSBD, hvm_featureset);
-
- sanitise_featureset(hvm_featureset);
- x86_cpu_featureset_to_policy(hvm_featureset, p);
- recalculate_xstate(p);
-}
-
-void __init init_guest_cpuid(void)
-{
- calculate_raw_policy();
- calculate_host_policy();
-
- if ( IS_ENABLED(CONFIG_PV) )
- {
- calculate_pv_max_policy();
- calculate_pv_def_policy();
- }
-
- if ( hvm_enabled )
- {
- calculate_hvm_max_policy();
- calculate_hvm_def_policy();
- }
-}
bool recheck_cpu_features(unsigned int cpu)
{
@@ -656,170 +32,6 @@ bool recheck_cpu_features(unsigned int cpu)
return okay;
}
-void recalculate_cpuid_policy(struct domain *d)
-{
- struct cpuid_policy *p = d->arch.cpuid;
- const struct cpuid_policy *max = is_pv_domain(d)
- ? (IS_ENABLED(CONFIG_PV) ? &pv_max_cpu_policy : NULL)
- : (IS_ENABLED(CONFIG_HVM) ? &hvm_max_cpu_policy : NULL);
- uint32_t fs[FSCAPINTS], max_fs[FSCAPINTS];
- unsigned int i;
-
- if ( !max )
- {
- ASSERT_UNREACHABLE();
- return;
- }
-
- p->x86_vendor = x86_cpuid_lookup_vendor(
- p->basic.vendor_ebx, p->basic.vendor_ecx, p->basic.vendor_edx);
-
- p->basic.max_leaf = min(p->basic.max_leaf, max->basic.max_leaf);
- p->feat.max_subleaf = min(p->feat.max_subleaf, max->feat.max_subleaf);
- p->extd.max_leaf = 0x80000000 | min(p->extd.max_leaf & 0xffff,
- ((p->x86_vendor & (X86_VENDOR_AMD |
-
X86_VENDOR_HYGON))
- ? CPUID_GUEST_NR_EXTD_AMD
- : CPUID_GUEST_NR_EXTD_INTEL) - 1);
-
- x86_cpu_policy_to_featureset(p, fs);
- x86_cpu_policy_to_featureset(max, max_fs);
-
- if ( is_hvm_domain(d) )
- {
- /*
- * HVM domains using Shadow paging have further restrictions on their
- * available paging features.
- */
- if ( !hap_enabled(d) )
- {
- for ( i = 0; i < ARRAY_SIZE(max_fs); i++ )
- max_fs[i] &= hvm_shadow_max_featuremask[i];
- }
-
- /* Hide nested-virt if it hasn't been explicitly configured. */
- if ( !nestedhvm_enabled(d) )
- {
- __clear_bit(X86_FEATURE_VMX, max_fs);
- __clear_bit(X86_FEATURE_SVM, max_fs);
- }
- }
-
- /*
- * Allow the toolstack to set HTT, X2APIC and CMP_LEGACY. These bits
- * affect how to interpret topology information in other cpuid leaves.
- */
- __set_bit(X86_FEATURE_HTT, max_fs);
- __set_bit(X86_FEATURE_X2APIC, max_fs);
- __set_bit(X86_FEATURE_CMP_LEGACY, max_fs);
-
- /*
- * 32bit PV domains can't use any Long Mode features, and cannot use
- * SYSCALL on non-AMD hardware.
- */
- if ( is_pv_32bit_domain(d) )
- {
- __clear_bit(X86_FEATURE_LM, max_fs);
- if ( !(boot_cpu_data.x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON))
)
- __clear_bit(X86_FEATURE_SYSCALL, max_fs);
- }
-
- /* Clamp the toolstacks choices to reality. */
- for ( i = 0; i < ARRAY_SIZE(fs); i++ )
- fs[i] &= max_fs[i];
-
- if ( p->basic.max_leaf < XSTATE_CPUID )
- __clear_bit(X86_FEATURE_XSAVE, fs);
-
- sanitise_featureset(fs);
-
- /* Fold host's FDP_EXCP_ONLY and NO_FPU_SEL into guest's view. */
- fs[FEATURESET_7b0] &= ~(cpufeat_mask(X86_FEATURE_FDP_EXCP_ONLY) |
- cpufeat_mask(X86_FEATURE_NO_FPU_SEL));
- fs[FEATURESET_7b0] |= (host_cpu_policy.feat._7b0 &
- (cpufeat_mask(X86_FEATURE_FDP_EXCP_ONLY) |
- cpufeat_mask(X86_FEATURE_NO_FPU_SEL)));
-
- x86_cpu_featureset_to_policy(fs, p);
-
- /* Pass host cacheline size through to guests. */
- p->basic.clflush_size = max->basic.clflush_size;
-
- p->extd.maxphysaddr = min(p->extd.maxphysaddr, max->extd.maxphysaddr);
- p->extd.maxphysaddr = min_t(uint8_t, p->extd.maxphysaddr,
- paging_max_paddr_bits(d));
- p->extd.maxphysaddr = max_t(uint8_t, p->extd.maxphysaddr,
- (p->basic.pae || p->basic.pse36) ? 36 : 32);
-
- p->extd.maxlinaddr = p->extd.lm ? 48 : 32;
-
- recalculate_xstate(p);
- recalculate_misc(p);
-
- for ( i = 0; i < ARRAY_SIZE(p->cache.raw); ++i )
- {
- if ( p->cache.subleaf[i].type >= 1 &&
- p->cache.subleaf[i].type <= 3 )
- {
- /* Subleaf has a valid cache type. Zero reserved fields. */
- p->cache.raw[i].a &= 0xffffc3ffu;
- p->cache.raw[i].d &= 0x00000007u;
- }
- else
- {
- /* Subleaf is not valid. Zero the rest of the union. */
- zero_leaves(p->cache.raw, i, ARRAY_SIZE(p->cache.raw) - 1);
- break;
- }
- }
-
- if ( vpmu_mode == XENPMU_MODE_OFF ||
- ((vpmu_mode & XENPMU_MODE_ALL) && !is_hardware_domain(d)) )
- p->basic.raw[0xa] = EMPTY_LEAF;
-
- if ( !p->extd.svm )
- p->extd.raw[0xa] = EMPTY_LEAF;
-
- if ( !p->extd.page1gb )
- p->extd.raw[0x19] = EMPTY_LEAF;
-}
-
-void __init init_dom0_cpuid_policy(struct domain *d)
-{
- struct cpuid_policy *p = d->arch.cpuid;
-
- /* dom0 can't migrate. Give it ITSC if available. */
- if ( cpu_has_itsc )
- p->extd.itsc = true;
-
- /*
- * Expose the "hardware speculation behaviour" bits of ARCH_CAPS to dom0,
- * so dom0 can turn off workarounds as appropriate. Temporary, until the
- * domain policy logic gains a better understanding of MSRs.
- */
- if ( cpu_has_arch_caps )
- p->feat.arch_caps = true;
-
- /* Apply dom0-cpuid= command line settings, if provided. */
- if ( dom0_cpuid_cmdline )
- {
- uint32_t fs[FSCAPINTS];
- unsigned int i;
-
- x86_cpu_policy_to_featureset(p, fs);
-
- for ( i = 0; i < ARRAY_SIZE(fs); ++i )
- {
- fs[i] |= dom0_enable_feat [i];
- fs[i] &= ~dom0_disable_feat[i];
- }
-
- x86_cpu_featureset_to_policy(fs, p);
-
- recalculate_cpuid_policy(d);
- }
-}
-
void guest_cpuid(const struct vcpu *v, uint32_t leaf,
uint32_t subleaf, struct cpuid_leaf *res)
{
@@ -1190,27 +402,6 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
}
}
-static void __init __maybe_unused build_assertions(void)
-{
- BUILD_BUG_ON(ARRAY_SIZE(known_features) != FSCAPINTS);
- BUILD_BUG_ON(ARRAY_SIZE(pv_max_featuremask) != FSCAPINTS);
- BUILD_BUG_ON(ARRAY_SIZE(hvm_shadow_max_featuremask) != FSCAPINTS);
- BUILD_BUG_ON(ARRAY_SIZE(hvm_hap_max_featuremask) != FSCAPINTS);
- BUILD_BUG_ON(ARRAY_SIZE(deep_features) != FSCAPINTS);
-
- /* Find some more clever allocation scheme if this trips. */
- BUILD_BUG_ON(sizeof(struct cpuid_policy) > PAGE_SIZE);
-
- BUILD_BUG_ON(sizeof(raw_cpu_policy.basic) !=
- sizeof(raw_cpu_policy.basic.raw));
- BUILD_BUG_ON(sizeof(raw_cpu_policy.feat) !=
- sizeof(raw_cpu_policy.feat.raw));
- BUILD_BUG_ON(sizeof(raw_cpu_policy.xstate) !=
- sizeof(raw_cpu_policy.xstate.raw));
- BUILD_BUG_ON(sizeof(raw_cpu_policy.extd) !=
- sizeof(raw_cpu_policy.extd.raw));
-}
-
/*
* Local variables:
* mode: C
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index d326fa1c01..675c523d99 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -77,7 +77,6 @@
#include <public/memory.h>
#include <public/vm_event.h>
#include <public/arch-x86/cpuid.h>
-#include <asm/cpuid.h>
#include <compat/hvm/hvm_op.h>
diff --git a/xen/arch/x86/include/asm/cpu-policy.h
b/xen/arch/x86/include/asm/cpu-policy.h
index 13e2a1f86d..b361537a60 100644
--- a/xen/arch/x86/include/asm/cpu-policy.h
+++ b/xen/arch/x86/include/asm/cpu-policy.h
@@ -18,4 +18,10 @@ void init_guest_cpu_policies(void);
/* Allocate and initialise a CPU policy suitable for the domain. */
int init_domain_cpu_policy(struct domain *d);
+/* Apply dom0-specific tweaks to the CPUID policy. */
+void init_dom0_cpuid_policy(struct domain *d);
+
+/* Clamp the CPUID policy to reality. */
+void recalculate_cpuid_policy(struct domain *d);
+
#endif /* X86_CPU_POLICY_H */
diff --git a/xen/arch/x86/include/asm/cpuid.h b/xen/arch/x86/include/asm/cpuid.h
index 7f81b998ce..b32ba0bbfe 100644
--- a/xen/arch/x86/include/asm/cpuid.h
+++ b/xen/arch/x86/include/asm/cpuid.h
@@ -8,14 +8,10 @@
#include <xen/kernel.h>
#include <xen/percpu.h>
-#include <xen/lib/x86/cpu-policy.h>
-
#include <public/sysctl.h>
extern const uint32_t known_features[FSCAPINTS];
-void init_guest_cpuid(void);
-
/*
* Expected levelling capabilities (given cpuid vendor/family information),
* and levelling capabilities actually available (given MSR probing).
@@ -49,13 +45,8 @@ extern struct cpuidmasks cpuidmask_defaults;
/* Check that all previously present features are still available. */
bool recheck_cpu_features(unsigned int cpu);
-/* Apply dom0-specific tweaks to the CPUID policy. */
-void init_dom0_cpuid_policy(struct domain *d);
-
-/* Clamp the CPUID policy to reality. */
-void recalculate_cpuid_policy(struct domain *d);
-
struct vcpu;
+struct cpuid_leaf;
void guest_cpuid(const struct vcpu *v, uint32_t leaf,
uint32_t subleaf, struct cpuid_leaf *res);
diff --git a/xen/arch/x86/pv/domain.c b/xen/arch/x86/pv/domain.c
index f94f28c8e2..95492715d8 100644
--- a/xen/arch/x86/pv/domain.c
+++ b/xen/arch/x86/pv/domain.c
@@ -10,6 +10,7 @@
#include <xen/param.h>
#include <xen/sched.h>
+#include <asm/cpu-policy.h>
#include <asm/cpufeature.h>
#include <asm/invpcid.h>
#include <asm/spec_ctrl.h>
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 51a19b9019..08ade715a3 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -51,7 +51,6 @@
#include <asm/alternative.h>
#include <asm/mc146818rtc.h>
#include <asm/cpu-policy.h>
-#include <asm/cpuid.h>
#include <asm/spec_ctrl.h>
#include <asm/guest.h>
#include <asm/microcode.h>
@@ -1991,7 +1990,6 @@ void __init noreturn __start_xen(unsigned long mbi_p)
if ( !tboot_protect_mem_regions() )
panic("Could not protect TXT memory regions\n");
- init_guest_cpuid();
init_guest_cpu_policies();
if ( xen_cpuidle )
--
generated by git-patchbot for /home/xen/git/xen.git#master
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