| Message ID | 20220221021922.733373-10-suravee.suthikulpanit@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introducing AMD x2APIC Virtualization (x2AVIC) support. | expand |
On Sun, 2022-02-20 at 20:19 -0600, Suravee Suthikulpanit wrote: > This function returns the currently programmed guest physical > APIC ID of a vCPU in both xAPIC and x2APIC modes. > In case of invalid APIC ID based on the current mode, > the function returns X2APIC_BROADCAST. > > Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> > --- > arch/x86/kvm/svm/avic.c | 29 ++++++++++++++++++++++++++--- > 1 file changed, 26 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c > index 55b3b703b93b..3543b7a4514a 100644 > --- a/arch/x86/kvm/svm/avic.c > +++ b/arch/x86/kvm/svm/avic.c > @@ -450,16 +450,35 @@ static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu) > clear_bit(AVIC_LOGICAL_ID_ENTRY_VALID_BIT, (unsigned long *)entry); > } > > +static inline u32 avic_get_apic_id(struct kvm_vcpu *vcpu) > +{ > + u32 apic_id = kvm_lapic_get_reg(vcpu->arch.apic, APIC_ID); > + > + if (!apic_x2apic_mode(vcpu->arch.apic)) { > + /* > + * In case of xAPIC, we do not support > + * APIC ID larger than 254. > + */ > + if (vcpu->vcpu_id >= APIC_BROADCAST) > + return X2APIC_BROADCAST; This is not a good way to return a error value like that IMHO. > + return apic_id >> 24; > + } else > + return apic_id; > +} I don't fully like this to be honest - this should be at least function in lapic.c and use kvm_xapic_id and kvm_x2apic_id. And hopefully if I manage to make apic id always read only then we be able to never use APIC_ID register and always use vcpu->vcpu_id. Best regards, Maxim Levitsky > + > static int avic_handle_ldr_update(struct kvm_vcpu *vcpu) > { > int ret = 0; > struct vcpu_svm *svm = to_svm(vcpu); > u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR); > - u32 id = kvm_xapic_id(vcpu->arch.apic); > + u32 id = avic_get_apic_id(vcpu); > > if (ldr == svm->ldr_reg) > return 0; > > + if (id == X2APIC_BROADCAST) > + return -EINVAL; > + This is what I mean. It is better to check here that we vcpu->vcpu_id >= APIC_BROADCAST and fail. > avic_invalidate_logical_id_entry(vcpu); > > if (ldr) > @@ -475,7 +494,10 @@ static int avic_handle_apic_id_update(struct kvm_vcpu *vcpu) > { > u64 *old, *new; > struct vcpu_svm *svm = to_svm(vcpu); > - u32 id = kvm_xapic_id(vcpu->arch.apic); > + u32 id = avic_get_apic_id(vcpu); > + > + if (id == X2APIC_BROADCAST) > + return 1; Same here. > > if (vcpu->vcpu_id == id) > return 0; > @@ -497,7 +519,8 @@ static int avic_handle_apic_id_update(struct kvm_vcpu *vcpu) > * APIC ID table entry if already setup the LDR. > */ > if (svm->ldr_reg) > - avic_handle_ldr_update(vcpu); > + if (avic_handle_ldr_update(vcpu)) > + return 1; > > return 0; Best regards, Maxim Levitsky > }
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 55b3b703b93b..3543b7a4514a 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -450,16 +450,35 @@ static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu) clear_bit(AVIC_LOGICAL_ID_ENTRY_VALID_BIT, (unsigned long *)entry); } +static inline u32 avic_get_apic_id(struct kvm_vcpu *vcpu) +{ + u32 apic_id = kvm_lapic_get_reg(vcpu->arch.apic, APIC_ID); + + if (!apic_x2apic_mode(vcpu->arch.apic)) { + /* + * In case of xAPIC, we do not support + * APIC ID larger than 254. + */ + if (vcpu->vcpu_id >= APIC_BROADCAST) + return X2APIC_BROADCAST; + return apic_id >> 24; + } else + return apic_id; +} + static int avic_handle_ldr_update(struct kvm_vcpu *vcpu) { int ret = 0; struct vcpu_svm *svm = to_svm(vcpu); u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR); - u32 id = kvm_xapic_id(vcpu->arch.apic); + u32 id = avic_get_apic_id(vcpu); if (ldr == svm->ldr_reg) return 0; + if (id == X2APIC_BROADCAST) + return -EINVAL; + avic_invalidate_logical_id_entry(vcpu); if (ldr) @@ -475,7 +494,10 @@ static int avic_handle_apic_id_update(struct kvm_vcpu *vcpu) { u64 *old, *new; struct vcpu_svm *svm = to_svm(vcpu); - u32 id = kvm_xapic_id(vcpu->arch.apic); + u32 id = avic_get_apic_id(vcpu); + + if (id == X2APIC_BROADCAST) + return 1; if (vcpu->vcpu_id == id) return 0; @@ -497,7 +519,8 @@ static int avic_handle_apic_id_update(struct kvm_vcpu *vcpu) * APIC ID table entry if already setup the LDR. */ if (svm->ldr_reg) - avic_handle_ldr_update(vcpu); + if (avic_handle_ldr_update(vcpu)) + return 1; return 0; }
This function returns the currently programmed guest physical APIC ID of a vCPU in both xAPIC and x2APIC modes. In case of invalid APIC ID based on the current mode, the function returns X2APIC_BROADCAST. Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> --- arch/x86/kvm/svm/avic.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-)