| Message ID | 20211012043535.500493-2-reijiw@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Make CPU ID registers writable by userspace | expand |
On Mon, Oct 11, 2021 at 09:35:11PM -0700, Reiji Watanabe wrote: > Introduce 'has_reset_once' flag in kvm_vcpu_arch, which indicates > if the vCPU reset has been done once, for later use. > > Signed-off-by: Reiji Watanabe <reijiw@google.com> > --- > arch/arm64/include/asm/kvm_host.h | 2 ++ > arch/arm64/kvm/reset.c | 4 ++++ > 2 files changed, 6 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index f8be56d5342b..9b5e7a3b6011 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -384,6 +384,7 @@ struct kvm_vcpu_arch { > u64 last_steal; > gpa_t base; > } steal; > + bool has_reset_once; > }; > > /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */ > @@ -449,6 +450,7 @@ struct kvm_vcpu_arch { > > #define vcpu_has_sve(vcpu) (system_supports_sve() && \ > ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE)) > +#define vcpu_has_reset_once(vcpu) ((vcpu)->arch.has_reset_once) > > #ifdef CONFIG_ARM64_PTR_AUTH > #define vcpu_has_ptrauth(vcpu) \ > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > index 5ce36b0a3343..4d34e5c1586c 100644 > --- a/arch/arm64/kvm/reset.c > +++ b/arch/arm64/kvm/reset.c > @@ -305,6 +305,10 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) > if (loaded) > kvm_arch_vcpu_load(vcpu, smp_processor_id()); > preempt_enable(); > + > + if (!ret && !vcpu->arch.has_reset_once) > + vcpu->arch.has_reset_once = true; > + > return ret; > } > > -- > 2.33.0.882.g93a45727a2-goog > Hi Reiji, Can't we use kvm_vcpu_initialized(vcpu)? vcpu->arch.target should only be >= when we've successfully reset the vcpu at least once. Thanks, drew
Hi Andrew, On Fri, Oct 15, 2021 at 3:13 AM Andrew Jones <drjones@redhat.com> wrote: > > On Mon, Oct 11, 2021 at 09:35:11PM -0700, Reiji Watanabe wrote: > > Introduce 'has_reset_once' flag in kvm_vcpu_arch, which indicates > > if the vCPU reset has been done once, for later use. > > > > Signed-off-by: Reiji Watanabe <reijiw@google.com> > > --- > > arch/arm64/include/asm/kvm_host.h | 2 ++ > > arch/arm64/kvm/reset.c | 4 ++++ > > 2 files changed, 6 insertions(+) > > > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > > index f8be56d5342b..9b5e7a3b6011 100644 > > --- a/arch/arm64/include/asm/kvm_host.h > > +++ b/arch/arm64/include/asm/kvm_host.h > > @@ -384,6 +384,7 @@ struct kvm_vcpu_arch { > > u64 last_steal; > > gpa_t base; > > } steal; > > + bool has_reset_once; > > }; > > > > /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */ > > @@ -449,6 +450,7 @@ struct kvm_vcpu_arch { > > > > #define vcpu_has_sve(vcpu) (system_supports_sve() && \ > > ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE)) > > +#define vcpu_has_reset_once(vcpu) ((vcpu)->arch.has_reset_once) > > > > #ifdef CONFIG_ARM64_PTR_AUTH > > #define vcpu_has_ptrauth(vcpu) \ > > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > > index 5ce36b0a3343..4d34e5c1586c 100644 > > --- a/arch/arm64/kvm/reset.c > > +++ b/arch/arm64/kvm/reset.c > > @@ -305,6 +305,10 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) > > if (loaded) > > kvm_arch_vcpu_load(vcpu, smp_processor_id()); > > preempt_enable(); > > + > > + if (!ret && !vcpu->arch.has_reset_once) > > + vcpu->arch.has_reset_once = true; > > + > > return ret; > > } > > > > -- > > 2.33.0.882.g93a45727a2-goog > > > > Hi Reiji, > > Can't we use kvm_vcpu_initialized(vcpu)? vcpu->arch.target should > only be >= when we've successfully reset the vcpu at least once. Thank you for reviewing the patch (and other patches as well) ! As you already noticed, we can't simply use kvm_vcpu_initialized() because vcpu->arch.target is currently set earlier than the first vcpu reset. Thanks, Reiji
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index f8be56d5342b..9b5e7a3b6011 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -384,6 +384,7 @@ struct kvm_vcpu_arch { u64 last_steal; gpa_t base; } steal; + bool has_reset_once; }; /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */ @@ -449,6 +450,7 @@ struct kvm_vcpu_arch { #define vcpu_has_sve(vcpu) (system_supports_sve() && \ ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE)) +#define vcpu_has_reset_once(vcpu) ((vcpu)->arch.has_reset_once) #ifdef CONFIG_ARM64_PTR_AUTH #define vcpu_has_ptrauth(vcpu) \ diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 5ce36b0a3343..4d34e5c1586c 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -305,6 +305,10 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) if (loaded) kvm_arch_vcpu_load(vcpu, smp_processor_id()); preempt_enable(); + + if (!ret && !vcpu->arch.has_reset_once) + vcpu->arch.has_reset_once = true; + return ret; }
Introduce 'has_reset_once' flag in kvm_vcpu_arch, which indicates if the vCPU reset has been done once, for later use. Signed-off-by: Reiji Watanabe <reijiw@google.com> --- arch/arm64/include/asm/kvm_host.h | 2 ++ arch/arm64/kvm/reset.c | 4 ++++ 2 files changed, 6 insertions(+)