| Message ID | 20210713163324.627647-10-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: vCPU RESET/INIT fixes and consolidation | expand |
On 13/07/21 18:32, Sean Christopherson wrote: > Drop an extra init_vmcb() from svm_create_vcpu(), svm_vcpu_reset() is > guaranteed to call init_vmcb() and there are no consumers of the VMCB > data between ->vcpu_create() and ->vcpu_reset(). Keep the call to > svm_switch_vmcb() as sev_es_create_vcpu() touches the current VMCB, but > hoist it up a few lines to associate the switch with the allocation of > vmcb01. > > Reviewed-by: Reiji Watanabe <reijiw@google.com> > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/kvm/svm/svm.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index 44248548be7d..cef9520fe77f 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -1431,15 +1431,13 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu) > > svm->vmcb01.ptr = page_address(vmcb01_page); > svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT); > + svm_switch_vmcb(svm, &svm->vmcb01); > > if (vmsa_page) > svm->vmsa = page_address(vmsa_page); > > svm->guest_state_loaded = false; > > - svm_switch_vmcb(svm, &svm->vmcb01); > - init_vmcb(vcpu); > - > svm_init_osvw(vcpu); > vcpu->arch.microcode_version = 0x01000065; While this patch makes sense, I'd rather not include it to reduce the part of the code in which svm->vmcb is NULL. See for example the issue reported by the static analyzer in which svm_hv_vmcb_dirty_nested_enlightenments (called by svm_vcpu_init_msrpm) dereferences svm->vmcb. Paolo
On Mon, Jul 26, 2021, Paolo Bonzini wrote: > On 13/07/21 18:32, Sean Christopherson wrote: > > Drop an extra init_vmcb() from svm_create_vcpu(), svm_vcpu_reset() is > > guaranteed to call init_vmcb() and there are no consumers of the VMCB > > data between ->vcpu_create() and ->vcpu_reset(). Keep the call to > > svm_switch_vmcb() as sev_es_create_vcpu() touches the current VMCB, but > > hoist it up a few lines to associate the switch with the allocation of > > vmcb01. > > > > Reviewed-by: Reiji Watanabe <reijiw@google.com> > > Signed-off-by: Sean Christopherson <seanjc@google.com> > > --- > > arch/x86/kvm/svm/svm.c | 4 +--- > > 1 file changed, 1 insertion(+), 3 deletions(-) > > > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > > index 44248548be7d..cef9520fe77f 100644 > > --- a/arch/x86/kvm/svm/svm.c > > +++ b/arch/x86/kvm/svm/svm.c > > @@ -1431,15 +1431,13 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu) > > svm->vmcb01.ptr = page_address(vmcb01_page); > > svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT); > > + svm_switch_vmcb(svm, &svm->vmcb01); > > if (vmsa_page) > > svm->vmsa = page_address(vmsa_page); > > svm->guest_state_loaded = false; > > - svm_switch_vmcb(svm, &svm->vmcb01); > > - init_vmcb(vcpu); > > - > > svm_init_osvw(vcpu); > > vcpu->arch.microcode_version = 0x01000065; > > While this patch makes sense, I'd rather not include it to reduce the part > of the code in which svm->vmcb is NULL. Not sure I follow. The svm_switch_vmcb() is kept, and even moved earlier.
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 44248548be7d..cef9520fe77f 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1431,15 +1431,13 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu) svm->vmcb01.ptr = page_address(vmcb01_page); svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT); + svm_switch_vmcb(svm, &svm->vmcb01); if (vmsa_page) svm->vmsa = page_address(vmsa_page); svm->guest_state_loaded = false; - svm_switch_vmcb(svm, &svm->vmcb01); - init_vmcb(vcpu); - svm_init_osvw(vcpu); vcpu->arch.microcode_version = 0x01000065;