Check "this" CPU instead of the boot CPU when querying SVM support so that the per-CPU checks done during hardware enabling actually function as intended, i.e. will detect issues where SVM isn't support on all CPUs. Disable migration for the use from svm_init() mostly so that the standard accessors for the per-CPU data can be used without getting yelled at by CONFIG_DEBUG_PREEMPT=y sanity checks. Preventing the "disabled by BIOS" error message from reporting the wrong CPU is largely a bonus, as ensuring a stable CPU during module load is a non-goal for KVM. Link: https://lore.kernel.org/all/ZAdxNgv0M6P63odE@xxxxxxxxxx Cc: Kai Huang <kai.huang@xxxxxxxxx> Cc: Chao Gao <chao.gao@xxxxxxxxx> Reviewed-by: Kai Huang <kai.huang@xxxxxxxxx> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- arch/x86/kvm/svm/svm.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index ff6c769aafb2..9e449167e71b 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -518,18 +518,20 @@ static void svm_init_osvw(struct kvm_vcpu *vcpu) vcpu->arch.osvw.status |= 1; } -static bool kvm_is_svm_supported(void) +static bool __kvm_is_svm_supported(void) { - int cpu = raw_smp_processor_id(); + int cpu = smp_processor_id(); + struct cpuinfo_x86 *c = &cpu_data(cpu); + u64 vm_cr; - if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD && - boot_cpu_data.x86_vendor != X86_VENDOR_HYGON) { + if (c->x86_vendor != X86_VENDOR_AMD && + c->x86_vendor != X86_VENDOR_HYGON) { pr_err("CPU %d isn't AMD or Hygon\n", cpu); return false; } - if (!boot_cpu_has(X86_FEATURE_SVM)) { + if (!cpu_has(c, X86_FEATURE_SVM)) { pr_err("SVM not supported by CPU %d\n", cpu); return false; } @@ -548,9 +550,20 @@ static bool kvm_is_svm_supported(void) return true; } +static bool kvm_is_svm_supported(void) +{ + bool supported; + + migrate_disable(); + supported = __kvm_is_svm_supported(); + migrate_enable(); + + return supported; +} + static int svm_check_processor_compat(void) { - if (!kvm_is_svm_supported()) + if (!__kvm_is_svm_supported()) return -EIO; return 0; -- 2.41.0.487.g6d72f3e995-goog
