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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging] tools/libxc: Rework xc_cpuid_apply_policy() to use {get, set}_cpu_policy()
commit 685e922d6f30f17cb6b902c25c21a5da7326738f
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Mon Sep 9 18:38:35 2019 +0100
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Thu Sep 26 13:40:18 2019 +0100
tools/libxc: Rework xc_cpuid_apply_policy() to use {get,set}_cpu_policy()
The purpose of this change is to stop using xc_cpuid_do_domctl(), and to
stop
basing decisions on a local CPUID instruction. This is not a correct or
appropriate way to construct policy information for other domains.
The overwhelming majority of this logic is redundant with the policy logic
in
Xen, but has a habit of becoming stale (e.g. c/s 97e4ebdcd76 resulting in
the
CPUID.7[1].eax not being offered to guests even when Xen is happy with the
content).
There are a few subtle side effects which need to remain in place. A
successful call to xc_cpuid_apply_policy() must result in a call to
xc_set_domain_cpu_policy() because that is currently the only way the
ITSC/VMX/SVM bits become reflected in the guests CPUID view. Future cleanup
will remove this side effect.
The topology tweaks are local to libxc. Extend struct cpuid_policy with
enough named fields to express the logic, but keep it identical to before.
Fixing topology representation is another future area of work.
No (expected) change in behaviour.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
Acked-by: Wei Liu <wl@xxxxxxx>
Release-acked-by: Juergen Gross <jgross@xxxxxxxx>
---
tools/libxc/xc_cpuid_x86.c | 833 ++++++++++------------------------------
xen/include/xen/lib/x86/cpuid.h | 11 +-
2 files changed, 219 insertions(+), 625 deletions(-)
diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c
index 43bda10d96..312c481f1e 100644
--- a/tools/libxc/xc_cpuid_x86.c
+++ b/tools/libxc/xc_cpuid_x86.c
@@ -34,18 +34,13 @@ enum {
#include <xen/asm/x86-vendors.h>
-#include <xen/lib/x86/cpuid.h>
-#include <xen/lib/x86/msr.h>
+#include <xen/lib/x86/cpu-policy.h>
#define bitmaskof(idx) (1u << ((idx) & 31))
#define featureword_of(idx) ((idx) >> 5)
#define clear_feature(idx, dst) ((dst) &= ~bitmaskof(idx))
#define set_feature(idx, dst) ((dst) |= bitmaskof(idx))
-#define DEF_MAX_BASE 0x0000000du
-#define DEF_MAX_INTELEXT 0x80000008u
-#define DEF_MAX_AMDEXT 0x8000001cu
-
int xc_get_cpu_levelling_caps(xc_interface *xch, uint32_t *caps)
{
DECLARE_SYSCTL;
@@ -282,622 +277,6 @@ int xc_set_domain_cpu_policy(xc_interface *xch, uint32_t
domid,
return ret;
}
-struct cpuid_domain_info
-{
- unsigned int vendor; /* X86_VENDOR_* */
-
- bool hvm;
- uint64_t xfeature_mask;
-
- /*
- * Careful with featureset lengths.
- *
- * Code in this file requires featureset to have at least
- * xc_get_cpu_featureset_size() entries. This is a libxc compiletime
- * constant.
- *
- * The featureset length used by the hypervisor may be different. If the
- * hypervisor version is longer, XEN_SYSCTL_get_cpu_featureset will fail
- * with -ENOBUFS, and libxc really does need rebuilding. If the
- * hypervisor version is shorter, it is safe to zero-extend.
- */
- uint32_t *featureset;
- unsigned int nr_features;
-
- /* PV-only information. */
- bool pv64;
-
- /* HVM-only information. */
- bool pae;
- bool nestedhvm;
-};
-
-static void cpuid(const unsigned int *input, unsigned int *regs)
-{
- unsigned int count = (input[1] == XEN_CPUID_INPUT_UNUSED) ? 0 : input[1];
-#ifdef __i386__
- /* Use the stack to avoid reg constraint failures with some gcc flags */
- asm (
- "push %%ebx; push %%edx\n\t"
- "cpuid\n\t"
- "mov %%ebx,4(%4)\n\t"
- "mov %%edx,12(%4)\n\t"
- "pop %%edx; pop %%ebx\n\t"
- : "=a" (regs[0]), "=c" (regs[2])
- : "0" (input[0]), "1" (count), "S" (regs)
- : "memory" );
-#else
- asm (
- "cpuid"
- : "=a" (regs[0]), "=b" (regs[1]), "=c" (regs[2]), "=d" (regs[3])
- : "0" (input[0]), "2" (count) );
-#endif
-}
-
-static int get_cpuid_domain_info(xc_interface *xch, uint32_t domid,
- struct cpuid_domain_info *info,
- const uint32_t *featureset,
- unsigned int nr_features)
-{
- struct xen_domctl domctl = {};
- xc_dominfo_t di;
- unsigned int in[2] = { 0, ~0U }, regs[4];
- unsigned int i, host_nr_features = xc_get_cpu_featureset_size();
- int rc;
-
- cpuid(in, regs);
- info->vendor = x86_cpuid_lookup_vendor(regs[1], regs[2], regs[3]);
-
- if ( xc_domain_getinfo(xch, domid, 1, &di) != 1 ||
- di.domid != domid )
- return -ESRCH;
-
- info->hvm = di.hvm;
-
- info->featureset = calloc(host_nr_features, sizeof(*info->featureset));
- if ( !info->featureset )
- return -ENOMEM;
-
- info->nr_features = host_nr_features;
-
- if ( featureset )
- {
- /*
- * The user supplied featureset may be shorter or longer than
- * host_nr_features. Shorter is fine, and we will zero-extend.
- * Longer is fine, so long as it only padded with zeros.
- */
- unsigned int fslen = min(host_nr_features, nr_features);
-
- memcpy(info->featureset, featureset,
- fslen * sizeof(*info->featureset));
-
- /* Check for truncated set bits. */
- for ( i = fslen; i < nr_features; ++i )
- if ( featureset[i] != 0 )
- return -EOPNOTSUPP;
- }
- else
- {
- rc = xc_get_cpu_featureset(xch, (info->hvm
- ? XEN_SYSCTL_cpu_featureset_hvm
- : XEN_SYSCTL_cpu_featureset_pv),
- &host_nr_features, info->featureset);
- if ( rc )
- return -errno;
- }
-
- /* Get xstate information. */
- domctl.cmd = XEN_DOMCTL_getvcpuextstate;
- domctl.domain = domid;
- rc = do_domctl(xch, &domctl);
- if ( rc )
- return -errno;
-
- info->xfeature_mask = domctl.u.vcpuextstate.xfeature_mask;
-
- if ( di.hvm )
- {
- uint64_t val;
-
- rc = xc_hvm_param_get(xch, domid, HVM_PARAM_PAE_ENABLED, &val);
- if ( rc )
- return -errno;
-
- info->pae = !!val;
-
- rc = xc_hvm_param_get(xch, domid, HVM_PARAM_NESTEDHVM, &val);
- if ( rc )
- return -errno;
-
- info->nestedhvm = !!val;
- }
- else
- {
- unsigned int width;
-
- rc = xc_domain_get_guest_width(xch, domid, &width);
- if ( rc )
- return -errno;
-
- info->pv64 = (width == 8);
- }
-
- return 0;
-}
-
-static void free_cpuid_domain_info(struct cpuid_domain_info *info)
-{
- free(info->featureset);
-}
-
-static void amd_xc_cpuid_policy(const struct cpuid_domain_info *info,
- const unsigned int *input, unsigned int *regs)
-{
- switch ( input[0] )
- {
- case 0x00000002:
- case 0x00000004:
- regs[0] = regs[1] = regs[2] = regs[3] = 0;
- break;
-
- case 0x80000000:
- if ( regs[0] > DEF_MAX_AMDEXT )
- regs[0] = DEF_MAX_AMDEXT;
- break;
-
- case 0x80000008:
- /*
- * ECX[15:12] is ApicIdCoreSize.
- * ECX[7:0] is NumberOfCores (minus one).
- * Update to reflect vLAPIC_ID = vCPU_ID * 2. But make sure to avoid
- * - overflow,
- * - going out of sync with leaf 1 EBX[23:16],
- * - incrementing ApicIdCoreSize when it's zero (which changes the
- * meaning of bits 7:0).
- */
- if ( (regs[2] & 0xffu) < 0x7fu )
- {
- if ( (regs[2] & 0xf000u) && (regs[2] & 0xf000u) != 0xf000u )
- regs[2] = ((regs[2] + 0x1000u) & 0xf000u) | (regs[2] & 0xffu);
- regs[2] = (regs[2] & 0xf000u) | ((regs[2] & 0x7fu) << 1) | 1u;
- }
- break;
-
- case 0x8000000a: {
- if ( !info->nestedhvm )
- {
- regs[0] = regs[1] = regs[2] = regs[3] = 0;
- break;
- }
-
-#define SVM_FEATURE_NPT 0x00000001 /* Nested page table support */
-#define SVM_FEATURE_LBRV 0x00000002 /* LBR virtualization support */
-#define SVM_FEATURE_SVML 0x00000004 /* SVM locking MSR support */
-#define SVM_FEATURE_NRIPS 0x00000008 /* Next RIP save on VMEXIT */
-#define SVM_FEATURE_TSCRATEMSR 0x00000010 /* TSC ratio MSR support */
-#define SVM_FEATURE_VMCBCLEAN 0x00000020 /* VMCB clean bits support */
-#define SVM_FEATURE_FLUSHBYASID 0x00000040 /* TLB flush by ASID support */
-#define SVM_FEATURE_DECODEASSISTS 0x00000080 /* Decode assists support */
-#define SVM_FEATURE_PAUSEFILTER 0x00000400 /* Pause intercept filter */
-
- /* Pass 1: Only passthrough SVM features which are
- * available in hw and which are implemented
- */
- regs[3] &= (SVM_FEATURE_NPT | SVM_FEATURE_LBRV | \
- SVM_FEATURE_NRIPS | SVM_FEATURE_PAUSEFILTER | \
- SVM_FEATURE_DECODEASSISTS);
-
- /* Pass 2: Always enable SVM features which are emulated */
- regs[3] |= SVM_FEATURE_VMCBCLEAN | SVM_FEATURE_TSCRATEMSR;
- break;
- }
-
- }
-}
-
-static void intel_xc_cpuid_policy(const struct cpuid_domain_info *info,
- const unsigned int *input, unsigned int
*regs)
-{
- switch ( input[0] )
- {
- case 0x00000004:
- /*
- * EAX[31:26] is Maximum Cores Per Package (minus one).
- * Update to reflect vLAPIC_ID = vCPU_ID * 2.
- */
- regs[0] = (((regs[0] & 0x7c000000u) << 1) | 0x04000000u |
- (regs[0] & 0x3ffu));
- regs[3] &= 0x3ffu;
- break;
-
- case 0x80000000:
- if ( regs[0] > DEF_MAX_INTELEXT )
- regs[0] = DEF_MAX_INTELEXT;
- break;
-
- case 0x80000005:
- regs[0] = regs[1] = regs[2] = 0;
- break;
-
- case 0x80000008:
- /* Mask AMD Number of Cores information. */
- regs[2] = 0;
- break;
- }
-}
-
-static void xc_cpuid_hvm_policy(const struct cpuid_domain_info *info,
- const unsigned int *input, unsigned int *regs)
-{
- switch ( input[0] )
- {
- case 0x00000000:
- if ( regs[0] > DEF_MAX_BASE )
- regs[0] = DEF_MAX_BASE;
- break;
-
- case 0x00000001:
- /*
- * EBX[23:16] is Maximum Logical Processors Per Package.
- * Update to reflect vLAPIC_ID = vCPU_ID * 2, but make sure to avoid
- * overflow.
- */
- if ( !(regs[1] & 0x00800000u) )
- regs[1] = (regs[1] & 0x0000ffffu) | ((regs[1] & 0x007f0000u) << 1);
- else
- regs[1] &= 0x00ffffffu;
-
- regs[2] = info->featureset[featureword_of(X86_FEATURE_SSE3)];
- regs[3] = (info->featureset[featureword_of(X86_FEATURE_FPU)] |
- bitmaskof(X86_FEATURE_HTT));
- break;
-
- case 0x00000007: /* Intel-defined CPU features */
- if ( input[1] == 0 )
- {
- regs[1] = info->featureset[featureword_of(X86_FEATURE_FSGSBASE)];
- regs[2] =
info->featureset[featureword_of(X86_FEATURE_PREFETCHWT1)];
- regs[3] =
info->featureset[featureword_of(X86_FEATURE_AVX512_4VNNIW)];
- }
- else
- {
- regs[1] = 0;
- regs[2] = 0;
- regs[3] = 0;
- }
- regs[0] = 0;
- break;
-
- case 0x0000000d: /* Xen automatically calculates almost everything. */
- if ( input[1] == 1 )
- regs[0] = info->featureset[featureword_of(X86_FEATURE_XSAVEOPT)];
- else
- regs[0] = 0;
- regs[1] = regs[2] = regs[3] = 0;
- break;
-
- case 0x80000000:
- /* Passthrough to cpu vendor specific functions */
- break;
-
- case 0x80000001:
- regs[2] = (info->featureset[featureword_of(X86_FEATURE_LAHF_LM)] &
- ~bitmaskof(X86_FEATURE_CMP_LEGACY));
- regs[3] = info->featureset[featureword_of(X86_FEATURE_SYSCALL)];
- break;
-
- case 0x80000007:
- /*
- * Keep only TSCInvariant. This may be cleared by the hypervisor
- * depending on guest TSC and migration settings.
- */
- regs[0] = regs[1] = regs[2] = 0;
- regs[3] &= 1u<<8;
- break;
-
- case 0x80000008:
- regs[0] &= 0x0000ffffu;
- regs[1] = info->featureset[featureword_of(X86_FEATURE_CLZERO)];
- /* regs[2] handled in the per-vendor logic. */
- regs[3] = 0;
- break;
-
- case 0x00000002: /* Intel cache info (dumped by AMD policy) */
- case 0x00000004: /* Intel cache info (dumped by AMD policy) */
- case 0x0000000a: /* Architectural Performance Monitor Features */
- case 0x80000002: /* Processor name string */
- case 0x80000003: /* ... continued */
- case 0x80000004: /* ... continued */
- case 0x80000005: /* AMD L1 cache/TLB info (dumped by Intel policy) */
- case 0x80000006: /* AMD L2/3 cache/TLB info ; Intel L2 cache features */
- case 0x8000000a: /* AMD SVM feature bits */
- case 0x80000019: /* AMD 1G TLB */
- case 0x8000001a: /* AMD perf hints */
- case 0x8000001c: /* AMD lightweight profiling */
- break;
-
- default:
- regs[0] = regs[1] = regs[2] = regs[3] = 0;
- break;
- }
-
- if ( info->vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON) )
- amd_xc_cpuid_policy(info, input, regs);
- else
- intel_xc_cpuid_policy(info, input, regs);
-}
-
-static void xc_cpuid_pv_policy(const struct cpuid_domain_info *info,
- const unsigned int *input, unsigned int *regs)
-{
- switch ( input[0] )
- {
- case 0x00000000:
- if ( regs[0] > DEF_MAX_BASE )
- regs[0] = DEF_MAX_BASE;
- break;
-
- case 0x00000001:
- {
- /* Host topology exposed to PV guest. Provide host value. */
- bool host_htt = regs[3] & bitmaskof(X86_FEATURE_HTT);
-
- /*
- * Don't pick host's Initial APIC ID which can change from run
- * to run.
- */
- regs[1] &= 0x00ffffffu;
-
- regs[2] = info->featureset[featureword_of(X86_FEATURE_SSE3)];
- regs[3] = (info->featureset[featureword_of(X86_FEATURE_FPU)] &
- ~bitmaskof(X86_FEATURE_HTT));
-
- if ( host_htt )
- regs[3] |= bitmaskof(X86_FEATURE_HTT);
- break;
- }
-
- case 0x00000007:
- if ( input[1] == 0 )
- {
- regs[1] = info->featureset[featureword_of(X86_FEATURE_FSGSBASE)];
- regs[2] =
info->featureset[featureword_of(X86_FEATURE_PREFETCHWT1)];
- regs[3] =
info->featureset[featureword_of(X86_FEATURE_AVX512_4VNNIW)];
- }
- else
- {
- regs[1] = 0;
- regs[2] = 0;
- regs[3] = 0;
- }
- regs[0] = 0;
- break;
-
- case 0x0000000d: /* Xen automatically calculates almost everything. */
- if ( input[1] == 1 )
- regs[0] = info->featureset[featureword_of(X86_FEATURE_XSAVEOPT)];
- else
- regs[0] = 0;
- regs[1] = regs[2] = regs[3] = 0;
- break;
-
- case 0x80000000:
- {
- unsigned int max = (info->vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON))
- ? DEF_MAX_AMDEXT : DEF_MAX_INTELEXT;
-
- if ( regs[0] > max )
- regs[0] = max;
- break;
- }
-
- case 0x80000001:
- {
- /* Host topology exposed to PV guest. Provide host CMP_LEGACY value.
*/
- bool host_cmp_legacy = regs[2] & bitmaskof(X86_FEATURE_CMP_LEGACY);
-
- regs[2] = (info->featureset[featureword_of(X86_FEATURE_LAHF_LM)] &
- ~bitmaskof(X86_FEATURE_CMP_LEGACY));
- regs[3] = info->featureset[featureword_of(X86_FEATURE_SYSCALL)];
-
- if ( host_cmp_legacy )
- regs[2] |= bitmaskof(X86_FEATURE_CMP_LEGACY);
-
- break;
- }
-
- case 0x80000008:
- regs[0] &= 0x0000ffffu;
- regs[1] = info->featureset[featureword_of(X86_FEATURE_CLZERO)];
- regs[2] = regs[3] = 0;
- break;
-
- case 0x00000005: /* MONITOR/MWAIT */
- case 0x0000000b: /* Extended Topology Enumeration */
- case 0x8000000a: /* SVM revision and features */
- case 0x8000001b: /* Instruction Based Sampling */
- case 0x8000001c: /* Light Weight Profiling */
- case 0x8000001e: /* Extended topology reporting */
- regs[0] = regs[1] = regs[2] = regs[3] = 0;
- break;
- }
-}
-
-static void xc_cpuid_policy(const struct cpuid_domain_info *info,
- const unsigned int *input, unsigned int *regs)
-{
- /*
- * For hypervisor leaves (0x4000XXXX) only 0x4000xx00.EAX[7:0] bits (max
- * number of leaves) can be set by user. Hypervisor will enforce this so
- * all other bits are don't-care and we can set them to zero.
- */
- if ( (input[0] & 0xffff0000) == 0x40000000 )
- {
- regs[0] = regs[1] = regs[2] = regs[3] = 0;
- return;
- }
-
- if ( info->hvm )
- xc_cpuid_hvm_policy(info, input, regs);
- else
- xc_cpuid_pv_policy(info, input, regs);
-}
-
-static int xc_cpuid_do_domctl(
- xc_interface *xch, uint32_t domid,
- const unsigned int *input, const unsigned int *regs)
-{
- DECLARE_DOMCTL;
-
- memset(&domctl, 0, sizeof (domctl));
- domctl.domain = domid;
- domctl.cmd = XEN_DOMCTL_set_cpuid;
- domctl.u.cpuid.input[0] = input[0];
- domctl.u.cpuid.input[1] = input[1];
- domctl.u.cpuid.eax = regs[0];
- domctl.u.cpuid.ebx = regs[1];
- domctl.u.cpuid.ecx = regs[2];
- domctl.u.cpuid.edx = regs[3];
-
- return do_domctl(xch, &domctl);
-}
-
-static void sanitise_featureset(struct cpuid_domain_info *info)
-{
- const uint32_t fs_size = xc_get_cpu_featureset_size();
- uint32_t disabled_features[fs_size];
- static const uint32_t deep_features[] = INIT_DEEP_FEATURES;
- unsigned int i, b;
-
- if ( info->hvm )
- {
- /* HVM or PVH Guest */
-
- if ( !info->pae )
- clear_bit(X86_FEATURE_PAE, info->featureset);
-
- if ( !info->nestedhvm )
- {
- clear_bit(X86_FEATURE_SVM, info->featureset);
- clear_bit(X86_FEATURE_VMX, info->featureset);
- }
- }
- else
- {
- /* PV Guest */
-
- if ( !info->pv64 )
- {
- clear_bit(X86_FEATURE_LM, info->featureset);
- if ( !(info->vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON)) )
- clear_bit(X86_FEATURE_SYSCALL, info->featureset);
- }
-
- clear_bit(X86_FEATURE_PSE, info->featureset);
- clear_bit(X86_FEATURE_PSE36, info->featureset);
- clear_bit(X86_FEATURE_PGE, info->featureset);
- clear_bit(X86_FEATURE_PAGE1GB, info->featureset);
- }
-
- if ( info->xfeature_mask == 0 )
- clear_bit(X86_FEATURE_XSAVE, info->featureset);
-
- /* Disable deep dependencies of disabled features. */
- for ( i = 0; i < ARRAY_SIZE(disabled_features); ++i )
- disabled_features[i] = ~info->featureset[i] & deep_features[i];
-
- for ( b = 0; b < sizeof(disabled_features) * CHAR_BIT; ++b )
- {
- const uint32_t *dfs;
-
- if ( !test_bit(b, disabled_features) ||
- !(dfs = x86_cpuid_lookup_deep_deps(b)) )
- continue;
-
- for ( i = 0; i < ARRAY_SIZE(disabled_features); ++i )
- {
- info->featureset[i] &= ~dfs[i];
- disabled_features[i] &= ~dfs[i];
- }
- }
-}
-
-int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid,
- const uint32_t *featureset, unsigned int nr_features)
-{
- struct cpuid_domain_info info = {};
- unsigned int input[2] = { 0, 0 }, regs[4];
- unsigned int base_max, ext_max;
- int rc;
-
- rc = get_cpuid_domain_info(xch, domid, &info, featureset, nr_features);
- if ( rc )
- goto out;
-
- cpuid(input, regs);
- base_max = (regs[0] <= DEF_MAX_BASE) ? regs[0] : DEF_MAX_BASE;
- input[0] = 0x80000000;
- cpuid(input, regs);
-
- if ( info.vendor == X86_VENDOR_AMD || info.vendor == X86_VENDOR_HYGON )
- ext_max = (regs[0] <= DEF_MAX_AMDEXT) ? regs[0] : DEF_MAX_AMDEXT;
- else
- ext_max = (regs[0] <= DEF_MAX_INTELEXT) ? regs[0] : DEF_MAX_INTELEXT;
-
- sanitise_featureset(&info);
-
- input[0] = 0;
- input[1] = XEN_CPUID_INPUT_UNUSED;
- for ( ; ; )
- {
- cpuid(input, regs);
- xc_cpuid_policy(&info, input, regs);
-
- if ( regs[0] || regs[1] || regs[2] || regs[3] )
- {
- rc = xc_cpuid_do_domctl(xch, domid, input, regs);
- if ( rc )
- goto out;
- }
-
- /* Intel cache descriptor leaves. */
- if ( input[0] == 4 )
- {
- input[1]++;
- /* More to do? Then loop keeping %%eax==0x00000004. */
- if ( (regs[0] & 0x1f) != 0 )
- continue;
- }
- /* Extended Topology leaves. */
- else if ( input[0] == 0xb )
- {
- uint8_t level_type = regs[2] >> 8;
-
- input[1]++;
- if ( level_type >= 1 && level_type <= 2 )
- continue;
- }
-
- input[0]++;
- if ( !(input[0] & 0x80000000u) && (input[0] > base_max ) )
- input[0] = 0x80000000u;
-
- input[1] = XEN_CPUID_INPUT_UNUSED;
- if ( (input[0] == 4) || (input[0] == 7) || (input[0] == 0xb) )
- input[1] = 0;
- else if ( input[0] == 0xd )
- input[1] = 1; /* Xen automatically calculates almost everything. */
-
- if ( (input[0] & 0x80000000u) && (input[0] > ext_max) )
- break;
- }
-
- out:
- free_cpuid_domain_info(&info);
- return rc;
-}
-
/*
* Configure a single input with the informatiom from config.
*
@@ -1074,3 +453,213 @@ int xc_cpuid_set(
return rc;
}
+
+int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid,
+ const uint32_t *featureset, unsigned int nr_features)
+{
+ int rc;
+ xc_dominfo_t di;
+ unsigned int i, nr_leaves, nr_msrs;
+ xen_cpuid_leaf_t *leaves = NULL;
+ struct cpuid_policy *p = NULL;
+ uint32_t err_leaf = -1, err_subleaf = -1, err_msr = -1;
+
+ if ( xc_domain_getinfo(xch, domid, 1, &di) != 1 ||
+ di.domid != domid )
+ {
+ ERROR("Failed to obtain d%d info", domid);
+ rc = -ESRCH;
+ goto out;
+ }
+
+ rc = xc_get_cpu_policy_size(xch, &nr_leaves, &nr_msrs);
+ if ( rc )
+ {
+ PERROR("Failed to obtain policy info size");
+ rc = -errno;
+ goto out;
+ }
+
+ rc = -ENOMEM;
+ if ( (leaves = calloc(nr_leaves, sizeof(*leaves))) == NULL ||
+ (p = calloc(1, sizeof(*p))) == NULL )
+ goto out;
+
+ /* Get the domain's default policy. */
+ nr_msrs = 0;
+ rc = xc_get_system_cpu_policy(xch, di.hvm ?
XEN_SYSCTL_cpu_policy_hvm_default
+ :
XEN_SYSCTL_cpu_policy_pv_default,
+ &nr_leaves, leaves, &nr_msrs, NULL);
+ if ( rc )
+ {
+ PERROR("Failed to obtain %s default policy", di.hvm ? "hvm" : "pv");
+ rc = -errno;
+ goto out;
+ }
+
+ rc = x86_cpuid_copy_from_buffer(p, leaves, nr_leaves,
+ &err_leaf, &err_subleaf);
+ if ( rc )
+ {
+ ERROR("Failed to deserialise CPUID (err leaf %#x, subleaf %#x) (%d =
%s)",
+ err_leaf, err_subleaf, -rc, strerror(-rc));
+ goto out;
+ }
+
+ if ( featureset )
+ {
+ uint32_t disabled_features[FEATURESET_NR_ENTRIES],
+ feat[FEATURESET_NR_ENTRIES] = {};
+ static const uint32_t deep_features[] = INIT_DEEP_FEATURES;
+ unsigned int i, b;
+
+ /*
+ * The user supplied featureset may be shorter or longer than
+ * FEATURESET_NR_ENTRIES. Shorter is fine, and we will zero-extend.
+ * Longer is fine, so long as it only padded with zeros.
+ */
+ unsigned int user_len = min(FEATURESET_NR_ENTRIES + 0u, nr_features);
+
+ /* Check for truncated set bits. */
+ rc = -EOPNOTSUPP;
+ for ( i = user_len; i < nr_features; ++i )
+ if ( featureset[i] != 0 )
+ goto out;
+
+ memcpy(feat, featureset, sizeof(*featureset) * user_len);
+
+ /* Disable deep dependencies of disabled features. */
+ for ( i = 0; i < ARRAY_SIZE(disabled_features); ++i )
+ disabled_features[i] = ~feat[i] & deep_features[i];
+
+ for ( b = 0; b < sizeof(disabled_features) * CHAR_BIT; ++b )
+ {
+ const uint32_t *dfs;
+
+ if ( !test_bit(b, disabled_features) ||
+ !(dfs = x86_cpuid_lookup_deep_deps(b)) )
+ continue;
+
+ for ( i = 0; i < ARRAY_SIZE(disabled_features); ++i )
+ {
+ feat[i] &= ~dfs[i];
+ disabled_features[i] &= ~dfs[i];
+ }
+ }
+
+ cpuid_featureset_to_policy(feat, p);
+ }
+
+ if ( !di.hvm )
+ {
+ uint32_t host_featureset[FEATURESET_NR_ENTRIES] = {};
+ uint32_t len = ARRAY_SIZE(host_featureset);
+
+ rc = xc_get_cpu_featureset(xch, XEN_SYSCTL_cpu_featureset_host,
+ &len, host_featureset);
+ if ( rc )
+ {
+ /* Tolerate "buffer too small", as we've got the bits we need. */
+ if ( errno == ENOBUFS )
+ rc = 0;
+ else
+ {
+ PERROR("Failed to obtain host featureset");
+ rc = -errno;
+ goto out;
+ }
+ }
+
+ /*
+ * On hardware without CPUID Faulting, PV guests see real topology.
+ * As a consequence, they also need to see the host htt/cmp fields.
+ */
+ p->basic.htt = test_bit(X86_FEATURE_HTT, host_featureset);
+ p->extd.cmp_legacy = test_bit(X86_FEATURE_CMP_LEGACY, host_featureset);
+ }
+ else
+ {
+ /*
+ * Topology for HVM guests is entirely controlled by Xen. For now, we
+ * hardcode APIC_ID = vcpu_id * 2 to give the illusion of no SMT.
+ */
+ p->basic.htt = true;
+ p->extd.cmp_legacy = false;
+
+ /*
+ * Leaf 1 EBX[23:16] is Maximum Logical Processors Per Package.
+ * Update to reflect vLAPIC_ID = vCPU_ID * 2, but make sure to avoid
+ * overflow.
+ */
+ if ( !(p->basic.lppp & 0x80) )
+ p->basic.lppp *= 2;
+
+ switch ( p->x86_vendor )
+ {
+ case X86_VENDOR_INTEL:
+ for ( i = 0; (p->cache.subleaf[i].type &&
+ i < ARRAY_SIZE(p->cache.raw)); ++i )
+ {
+ p->cache.subleaf[i].cores_per_package =
+ (p->cache.subleaf[i].cores_per_package << 1) | 1;
+ p->cache.subleaf[i].threads_per_cache = 0;
+ }
+ break;
+
+ case X86_VENDOR_AMD:
+ case X86_VENDOR_HYGON:
+ /*
+ * Leaf 0x80000008 ECX[15:12] is ApicIdCoreSize.
+ * Leaf 0x80000008 ECX[7:0] is NumberOfCores (minus one).
+ * Update to reflect vLAPIC_ID = vCPU_ID * 2. But avoid
+ * - overflow,
+ * - going out of sync with leaf 1 EBX[23:16],
+ * - incrementing ApicIdCoreSize when it's zero (which changes the
+ * meaning of bits 7:0).
+ */
+ if ( p->extd.nc < 0x7f )
+ {
+ if ( p->extd.apic_id_size != 0 && p->extd.apic_id_size != 0xf )
+ p->extd.apic_id_size++;
+
+ p->extd.nc = (p->extd.nc << 1) | 1;
+ }
+ break;
+ }
+
+ /*
+ * These settings are necessary to cause earlier HVM_PARAM_NESTEDHVM /
+ * XEN_DOMCTL_disable_migrate settings to be reflected correctly in
+ * CPUID. Xen will discard these bits if configuration hasn't been
+ * set for the domain.
+ */
+ p->extd.itsc = true;
+ p->basic.vmx = true;
+ p->extd.svm = true;
+ }
+
+ rc = x86_cpuid_copy_to_buffer(p, leaves, &nr_leaves);
+ if ( rc )
+ {
+ ERROR("Failed to serialise CPUID (%d = %s)", -rc, strerror(-rc));
+ goto out;
+ }
+
+ rc = xc_set_domain_cpu_policy(xch, domid, nr_leaves, leaves, 0, NULL,
+ &err_leaf, &err_subleaf, &err_msr);
+ if ( rc )
+ {
+ PERROR("Failed to set d%d's policy (err leaf %#x, subleaf %#x, msr
%#x)",
+ domid, err_leaf, err_subleaf, err_msr);
+ rc = -errno;
+ goto out;
+ }
+
+ rc = 0;
+
+out:
+ free(p);
+ free(leaves);
+
+ return rc;
+}
diff --git a/xen/include/xen/lib/x86/cpuid.h b/xen/include/xen/lib/x86/cpuid.h
index 79840f99ce..331ef4f4f0 100644
--- a/xen/include/xen/lib/x86/cpuid.h
+++ b/xen/include/xen/lib/x86/cpuid.h
@@ -154,8 +154,12 @@ struct cpuid_policy
union {
struct cpuid_leaf raw[CPUID_GUEST_NR_CACHE];
struct cpuid_cache_leaf {
- uint32_t type:5,
- :27, :32, :32, :32;
+ uint32_t /* a */ type:5, level:3;
+ bool self_init:1, fully_assoc:1;
+ uint32_t :4, threads_per_cache:12, cores_per_package:6;
+ uint32_t /* b */ line_size:12, partitions:10, ways:10;
+ uint32_t /* c */ sets;
+ bool /* d */ wbinvd:1, inclusive:1, complex:1;
} subleaf[CPUID_GUEST_NR_CACHE];
} cache;
@@ -259,7 +263,8 @@ struct cpuid_policy
uint32_t e8b;
struct { DECL_BITFIELD(e8b); };
};
- uint32_t /* c */:32, /* d */:32;
+ uint32_t nc:8, :4, apic_id_size:4, :16;
+ uint32_t /* d */:32;
};
} extd;
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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