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| author | Maxim Levitsky <mlevitsk@redhat.com> | 2021-07-07 15:51:00 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-07-15 10:19:42 -0400 |
| commit | 4b639a9f82fcf15497d1613a29aa1df798a24029 (patch) | |
| tree | 9bd5b1b7617f582c24a9a1ebe4570ea6e74e7f59 /arch | |
| parent | 896707c212d440a6863ce0a3930c8a609e24497d (diff) | |
| download | linux-4b639a9f82fcf15497d1613a29aa1df798a24029.tar.bz2 | |
KVM: SVM: add module param to control the #SMI interception
In theory there are no side effects of not intercepting #SMI,
because then #SMI becomes transparent to the OS and the KVM.
Plus an observation on recent Zen2 CPUs reveals that these
CPUs ignore #SMI interception and never deliver #SMI VMexits.
This is also useful to test nested KVM to see that L1
handles #SMIs correctly in case when L1 doesn't intercept #SMI.
Finally the default remains the same, the SMI are intercepted
by default thus this patch doesn't have any effect unless
non default module param value is used.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210707125100.677203-4-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 10 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 1 |
3 files changed, 14 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 21d03e3a5dfd..2884c54a72bb 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -154,6 +154,10 @@ void recalc_intercepts(struct vcpu_svm *svm) for (i = 0; i < MAX_INTERCEPT; i++) c->intercepts[i] |= g->intercepts[i]; + + /* If SMI is not intercepted, ignore guest SMI intercept as well */ + if (!intercept_smi) + vmcb_clr_intercept(c, INTERCEPT_SMI); } static void copy_vmcb_control_area(struct vmcb_control_area *dst, diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 18aa4d45cc64..63488d3beb5b 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -198,6 +198,11 @@ module_param(avic, bool, 0444); bool __read_mostly dump_invalid_vmcb; module_param(dump_invalid_vmcb, bool, 0644); + +bool intercept_smi = true; +module_param(intercept_smi, bool, 0444); + + static bool svm_gp_erratum_intercept = true; static u8 rsm_ins_bytes[] = "\x0f\xaa"; @@ -1185,7 +1190,10 @@ static void init_vmcb(struct kvm_vcpu *vcpu) svm_set_intercept(svm, INTERCEPT_INTR); svm_set_intercept(svm, INTERCEPT_NMI); - svm_set_intercept(svm, INTERCEPT_SMI); + + if (intercept_smi) + svm_set_intercept(svm, INTERCEPT_SMI); + svm_set_intercept(svm, INTERCEPT_SELECTIVE_CR0); svm_set_intercept(svm, INTERCEPT_RDPMC); svm_set_intercept(svm, INTERCEPT_CPUID); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index f89b623bb591..8cb3bd59c5ea 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -31,6 +31,7 @@ #define MSRPM_OFFSETS 16 extern u32 msrpm_offsets[MSRPM_OFFSETS] __read_mostly; extern bool npt_enabled; +extern bool intercept_smi; /* * Clean bits in VMCB. |