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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen stable-4.16] x86/spec-ctrl: Remove opencoded MSR_ARCH_CAPS check
commit 976e4a890ebdd05f8f14b7f1e250be2782ffcf4a
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Mon May 15 19:15:48 2023 +0100
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Tue Aug 8 16:02:54 2023 +0100
x86/spec-ctrl: Remove opencoded MSR_ARCH_CAPS check
MSR_ARCH_CAPS data is now included in featureset information. Replace
opencoded checks with regular feature ones.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
(cherry picked from commit 511b9f286c3dadd041e0d90beeff7d47c9bf3b7a)
---
xen/arch/x86/spec_ctrl.c | 56 +++++++++++++++++++---------------------
xen/include/asm-x86/cpufeature.h | 7 +++++
2 files changed, 33 insertions(+), 30 deletions(-)
diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c
index 14649d92f5..242ff65529 100644
--- a/xen/arch/x86/spec_ctrl.c
+++ b/xen/arch/x86/spec_ctrl.c
@@ -293,12 +293,10 @@ custom_param("spec-ctrl", parse_spec_ctrl);
int8_t __read_mostly opt_xpti_hwdom = -1;
int8_t __read_mostly opt_xpti_domu = -1;
-static __init void xpti_init_default(uint64_t caps)
+static __init void xpti_init_default(void)
{
- if ( boot_cpu_data.x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON) )
- caps = ARCH_CAPS_RDCL_NO;
-
- if ( caps & ARCH_CAPS_RDCL_NO )
+ if ( (boot_cpu_data.x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON)) ||
+ cpu_has_rdcl_no )
{
if ( opt_xpti_hwdom < 0 )
opt_xpti_hwdom = 0;
@@ -401,9 +399,10 @@ static __init int parse_pv_l1tf(const char *s)
}
custom_param("pv-l1tf", parse_pv_l1tf);
-static void __init print_details(enum ind_thunk thunk, uint64_t caps)
+static void __init print_details(enum ind_thunk thunk)
{
unsigned int _7d0 = 0, _7d2 = 0, e8b = 0, max = 0, tmp;
+ uint64_t caps = 0;
/* Collect diagnostics about available mitigations. */
if ( boot_cpu_data.cpuid_level >= 7 )
@@ -412,6 +411,8 @@ static void __init print_details(enum ind_thunk thunk,
uint64_t caps)
cpuid_count(7, 2, &tmp, &tmp, &tmp, &_7d2);
if ( boot_cpu_data.extended_cpuid_level >= 0x80000008 )
cpuid(0x80000008, &tmp, &e8b, &tmp, &tmp);
+ if ( cpu_has_arch_caps )
+ rdmsrl(MSR_ARCH_CAPABILITIES, caps);
printk("Speculative mitigation facilities:\n");
@@ -585,7 +586,7 @@ static bool __init check_smt_enabled(void)
}
/* Calculate whether Retpoline is known-safe on this CPU. */
-static bool __init retpoline_safe(uint64_t caps)
+static bool __init retpoline_safe(void)
{
unsigned int ucode_rev = this_cpu(cpu_sig).rev;
@@ -603,7 +604,7 @@ static bool __init retpoline_safe(uint64_t caps)
* Processors offering Enhanced IBRS are not guarenteed to be
* repoline-safe.
*/
- if ( caps & (ARCH_CAPS_RSBA | ARCH_CAPS_IBRS_ALL) )
+ if ( cpu_has_rsba || cpu_has_eibrs )
return false;
switch ( boot_cpu_data.x86_model )
@@ -852,7 +853,7 @@ static void __init ibpb_calculations(void)
}
/* Calculate whether this CPU is vulnerable to L1TF. */
-static __init void l1tf_calculations(uint64_t caps)
+static __init void l1tf_calculations(void)
{
bool hit_default = false;
@@ -940,7 +941,7 @@ static __init void l1tf_calculations(uint64_t caps)
}
/* Any processor advertising RDCL_NO should be not vulnerable to L1TF. */
- if ( caps & ARCH_CAPS_RDCL_NO )
+ if ( cpu_has_rdcl_no )
cpu_has_bug_l1tf = false;
if ( cpu_has_bug_l1tf && hit_default )
@@ -999,7 +1000,7 @@ static __init void l1tf_calculations(uint64_t caps)
}
/* Calculate whether this CPU is vulnerable to MDS. */
-static __init void mds_calculations(uint64_t caps)
+static __init void mds_calculations(void)
{
/* MDS is only known to affect Intel Family 6 processors at this time. */
if ( boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
@@ -1007,7 +1008,7 @@ static __init void mds_calculations(uint64_t caps)
return;
/* Any processor advertising MDS_NO should be not vulnerable to MDS. */
- if ( caps & ARCH_CAPS_MDS_NO )
+ if ( cpu_has_mds_no )
return;
switch ( boot_cpu_data.x86_model )
@@ -1120,10 +1121,6 @@ void __init init_speculation_mitigations(void)
enum ind_thunk thunk = THUNK_DEFAULT;
bool has_spec_ctrl, ibrs = false, hw_smt_enabled;
bool cpu_has_bug_taa;
- uint64_t caps = 0;
-
- if ( cpu_has_arch_caps )
- rdmsrl(MSR_ARCH_CAPABILITIES, caps);
hw_smt_enabled = check_smt_enabled();
@@ -1170,7 +1167,7 @@ void __init init_speculation_mitigations(void)
* On all hardware, we'd like to use retpoline in preference to
* IBRS, but only if it is safe on this hardware.
*/
- if ( retpoline_safe(caps) )
+ if ( retpoline_safe() )
thunk = THUNK_RETPOLINE;
else if ( has_spec_ctrl )
ibrs = true;
@@ -1394,13 +1391,13 @@ void __init init_speculation_mitigations(void)
* threads. Activate this if SMT is enabled, and Xen is using a non-zero
* MSR_SPEC_CTRL setting.
*/
- if ( boot_cpu_has(X86_FEATURE_IBRSB) && !(caps & ARCH_CAPS_IBRS_ALL) &&
+ if ( boot_cpu_has(X86_FEATURE_IBRSB) && !cpu_has_eibrs &&
hw_smt_enabled && default_xen_spec_ctrl )
setup_force_cpu_cap(X86_FEATURE_SC_MSR_IDLE);
- xpti_init_default(caps);
+ xpti_init_default();
- l1tf_calculations(caps);
+ l1tf_calculations();
/*
* By default, enable PV domU L1TF mitigations on all L1TF-vulnerable
@@ -1421,7 +1418,7 @@ void __init init_speculation_mitigations(void)
if ( !boot_cpu_has(X86_FEATURE_L1D_FLUSH) )
opt_l1d_flush = 0;
else if ( opt_l1d_flush == -1 )
- opt_l1d_flush = cpu_has_bug_l1tf && !(caps & ARCH_CAPS_SKIP_L1DFL);
+ opt_l1d_flush = cpu_has_bug_l1tf && !cpu_has_skip_l1dfl;
/* We compile lfence's in by default, and nop them out if requested. */
if ( !opt_branch_harden )
@@ -1444,7 +1441,7 @@ void __init init_speculation_mitigations(void)
"enabled. Please assess your configuration and choose an\n"
"explicit 'smt=<bool>' setting. See XSA-273.\n");
- mds_calculations(caps);
+ mds_calculations();
/*
* Parts which enumerate FB_CLEAR are those which are post-MDS_NO and have
@@ -1456,7 +1453,7 @@ void __init init_speculation_mitigations(void)
* the return-to-guest path.
*/
if ( opt_unpriv_mmio )
- opt_fb_clear_mmio = caps & ARCH_CAPS_FB_CLEAR;
+ opt_fb_clear_mmio = cpu_has_fb_clear;
/*
* By default, enable PV and HVM mitigations on MDS-vulnerable hardware.
@@ -1486,7 +1483,7 @@ void __init init_speculation_mitigations(void)
*/
if ( opt_md_clear_pv || opt_md_clear_hvm || opt_fb_clear_mmio )
setup_force_cpu_cap(X86_FEATURE_SC_VERW_IDLE);
- opt_md_clear_hvm &= !(caps & ARCH_CAPS_SKIP_L1DFL) && !opt_l1d_flush;
+ opt_md_clear_hvm &= !cpu_has_skip_l1dfl && !opt_l1d_flush;
/*
* Warn the user if they are on MLPDS/MFBDS-vulnerable hardware with HT
@@ -1517,8 +1514,7 @@ void __init init_speculation_mitigations(void)
* we check both to spot TSX in a microcode/cmdline independent way.
*/
cpu_has_bug_taa =
- (cpu_has_rtm || (caps & ARCH_CAPS_TSX_CTRL)) &&
- (caps & (ARCH_CAPS_MDS_NO | ARCH_CAPS_TAA_NO)) == ARCH_CAPS_MDS_NO;
+ (cpu_has_rtm || cpu_has_tsx_ctrl) && cpu_has_mds_no && !cpu_has_taa_no;
/*
* On TAA-affected hardware, disabling TSX is the preferred mitigation, vs
@@ -1537,7 +1533,7 @@ void __init init_speculation_mitigations(void)
* plausibly value TSX higher than Hyperthreading...), disable TSX to
* mitigate TAA.
*/
- if ( opt_tsx == -1 && cpu_has_bug_taa && (caps & ARCH_CAPS_TSX_CTRL) &&
+ if ( opt_tsx == -1 && cpu_has_bug_taa && cpu_has_tsx_ctrl &&
((hw_smt_enabled && opt_smt) ||
!boot_cpu_has(X86_FEATURE_SC_VERW_IDLE)) )
{
@@ -1562,15 +1558,15 @@ void __init init_speculation_mitigations(void)
if ( cpu_has_srbds_ctrl )
{
if ( opt_srb_lock == -1 && !opt_unpriv_mmio &&
- (caps & (ARCH_CAPS_MDS_NO|ARCH_CAPS_TAA_NO)) == ARCH_CAPS_MDS_NO
&&
- (!cpu_has_hle || ((caps & ARCH_CAPS_TSX_CTRL) && rtm_disabled)) )
+ cpu_has_mds_no && !cpu_has_taa_no &&
+ (!cpu_has_hle || (cpu_has_tsx_ctrl && rtm_disabled)) )
opt_srb_lock = 0;
set_in_mcu_opt_ctrl(MCU_OPT_CTRL_RNGDS_MITG_DIS,
opt_srb_lock ? 0 : MCU_OPT_CTRL_RNGDS_MITG_DIS);
}
- print_details(thunk, caps);
+ print_details(thunk);
/*
* If MSR_SPEC_CTRL is available, apply Xen's default setting and discard
diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
index 1ab0602524..8216e52c08 100644
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -144,8 +144,15 @@
#define cpu_has_avx512_bf16 boot_cpu_has(X86_FEATURE_AVX512_BF16)
/* MSR_ARCH_CAPS */
+#define cpu_has_rdcl_no boot_cpu_has(X86_FEATURE_RDCL_NO)
+#define cpu_has_eibrs boot_cpu_has(X86_FEATURE_EIBRS)
+#define cpu_has_rsba boot_cpu_has(X86_FEATURE_RSBA)
+#define cpu_has_skip_l1dfl boot_cpu_has(X86_FEATURE_SKIP_L1DFL)
+#define cpu_has_mds_no boot_cpu_has(X86_FEATURE_MDS_NO)
#define cpu_has_if_pschange_mc_no boot_cpu_has(X86_FEATURE_IF_PSCHANGE_MC_NO)
#define cpu_has_tsx_ctrl boot_cpu_has(X86_FEATURE_TSX_CTRL)
+#define cpu_has_taa_no boot_cpu_has(X86_FEATURE_TAA_NO)
+#define cpu_has_fb_clear boot_cpu_has(X86_FEATURE_FB_CLEAR)
/* Synthesized. */
#define cpu_has_arch_perfmon boot_cpu_has(X86_FEATURE_ARCH_PERFMON)
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.16
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