[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen stable-4.16] x86/amd: Introduce is_zen{1,2}_uarch() predicates
commit a5857f1eca17a609119ae928c9fa73bb0996ddd9 Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> AuthorDate: Fri Sep 15 12:13:51 2023 +0100 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Tue Sep 19 19:38:04 2023 +0100 x86/amd: Introduce is_zen{1,2}_uarch() predicates We already have 3 cases using STIBP as a Zen1/2 heuristic, and are about to introduce a 4th. Wrap the heuristic into a pair of predicates rather than opencoding it, and the explanation of the heuristic, at each usage site. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> (cherry picked from commit de1d265001397f308c5c3c5d3ffc30e7ef8c0705) --- xen/arch/x86/cpu/amd.c | 18 ++++-------------- xen/include/asm-x86/amd.h | 11 +++++++++++ 2 files changed, 15 insertions(+), 14 deletions(-) diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c index a591038757..b71d891901 100644 --- a/xen/arch/x86/cpu/amd.c +++ b/xen/arch/x86/cpu/amd.c @@ -746,15 +746,13 @@ void amd_init_ssbd(const struct cpuinfo_x86 *c) * non-branch instructions to be ignored. It is to be set unilaterally in * newer microcode. * - * This chickenbit is something unrelated on Zen1, and Zen1 vs Zen2 isn't a - * simple model number comparison, so use STIBP as a heuristic to separate the - * two uarches in Fam17h(AMD)/18h(Hygon). + * This chickenbit is something unrelated on Zen1. */ void amd_init_spectral_chicken(void) { uint64_t val, chickenbit = 1 << 1; - if (cpu_has_hypervisor || !boot_cpu_has(X86_FEATURE_AMD_STIBP)) + if (cpu_has_hypervisor || !is_zen2_uarch()) return; if (rdmsr_safe(MSR_AMD64_DE_CFG2, val) == 0 && !(val & chickenbit)) @@ -803,11 +801,8 @@ void amd_check_zenbleed(void) * With the Fam17h check above, most parts getting here are * Zen1. They're not affected. Assume Zen2 ones making it * here are affected regardless of microcode version. - * - * Zen1 vs Zen2 isn't a simple model number comparison, so use - * STIBP as a heuristic to distinguish. */ - if (!boot_cpu_has(X86_FEATURE_AMD_STIBP)) + if (is_zen1_uarch()) return; good_rev = ~0U; break; @@ -1168,12 +1163,7 @@ static int __init zen2_c6_errata_check(void) */ s_time_t delta; - /* - * Zen1 vs Zen2 isn't a simple model number comparison, so use STIBP as - * a heuristic to separate the two uarches in Fam17h. - */ - if (cpu_has_hypervisor || boot_cpu_data.x86 != 0x17 || - !boot_cpu_has(X86_FEATURE_AMD_STIBP)) + if (cpu_has_hypervisor || boot_cpu_data.x86 != 0x17 || !is_zen2_uarch()) return 0; /* diff --git a/xen/include/asm-x86/amd.h b/xen/include/asm-x86/amd.h index a82382e6bf..7fe1e19217 100644 --- a/xen/include/asm-x86/amd.h +++ b/xen/include/asm-x86/amd.h @@ -140,6 +140,17 @@ AMD_MODEL_RANGE(0x11, 0x0, 0x0, 0xff, 0xf), \ AMD_MODEL_RANGE(0x12, 0x0, 0x0, 0xff, 0xf)) +/* + * The Zen1 and Zen2 microarchitectures are implemented by AMD (Fam17h) and + * Hygon (Fam18h) but without simple model number rules. Instead, use STIBP + * as a heuristic that distinguishes the two. + * + * The caller is required to perform the appropriate vendor/family checks + * first. + */ +#define is_zen1_uarch() (!boot_cpu_has(X86_FEATURE_AMD_STIBP)) +#define is_zen2_uarch() boot_cpu_has(X86_FEATURE_AMD_STIBP) + struct cpuinfo_x86; int cpu_has_amd_erratum(const struct cpuinfo_x86 *, int, ...); -- generated by git-patchbot for /home/xen/git/xen.git#stable-4.16
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