| Message ID | 20180112120747.27999-6-christoffer.dall@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 01/12/2018 12:07 PM, Christoffer Dall wrote: > From: Shih-Wei Li <shihwei@cs.columbia.edu> > > We always set the IMO and FMO bits in the HCR_EL2 when running the > guest, regardless if we use the vgic or not. By moving these flags to > HCR_GUEST_FLAGS we can avoid one of the extra save/restore operations of > HCR_EL2 in the world switch code, and we can also soon get rid of the > other one. > > This is safe, because even though the IMO and FMO bits control both > taking the interrupts to EL2 and remapping ICC_*_EL1 to ICV_*_EL1 > executed at EL1, as long as we ensure that these bits are clear when > running the EL1 host, as defined in the HCR_HOST_[VHE_]FLAGS, we're OK. NIT: I was a bit confused by the end of the sentence because HCR_HOST_FLAGS define does not seem to exist. > > Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> > Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu> > Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> > --- > arch/arm64/include/asm/kvm_arm.h | 4 ++-- > arch/arm64/kvm/hyp/switch.c | 3 --- > 2 files changed, 2 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h > index 715d395ef45b..656deeb17bf2 100644 > --- a/arch/arm64/include/asm/kvm_arm.h > +++ b/arch/arm64/include/asm/kvm_arm.h > @@ -79,9 +79,9 @@ > */ > #define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \ > HCR_TVM | HCR_BSU_IS | HCR_FB | HCR_TAC | \ > - HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW) > + HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | \ > + HCR_FMO | HCR_IMO) > #define HCR_VIRT_EXCP_MASK (HCR_VSE | HCR_VI | HCR_VF) > -#define HCR_INT_OVERRIDE (HCR_FMO | HCR_IMO) > #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) > > /* TCR_EL2 Registers bits */ > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > index 71700ecee308..f6189d08753e 100644 > --- a/arch/arm64/kvm/hyp/switch.c > +++ b/arch/arm64/kvm/hyp/switch.c > @@ -167,8 +167,6 @@ static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu) > __vgic_v3_save_state(vcpu); > else > __vgic_v2_save_state(vcpu); > - > - write_sysreg(read_sysreg(hcr_el2) & ~HCR_INT_OVERRIDE, hcr_el2); > } > > static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu) > @@ -176,7 +174,6 @@ static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu) > u64 val; > > val = read_sysreg(hcr_el2); > - val |= HCR_INT_OVERRIDE; > val |= vcpu->arch.irq_lines; > write_sysreg(val, hcr_el2); > > Cheers,
On Fri, Feb 09, 2018 at 11:38:50AM +0000, Julien Grall wrote: > Hi, > > On 01/12/2018 12:07 PM, Christoffer Dall wrote: > >From: Shih-Wei Li <shihwei@cs.columbia.edu> > > > >We always set the IMO and FMO bits in the HCR_EL2 when running the > >guest, regardless if we use the vgic or not. By moving these flags to > >HCR_GUEST_FLAGS we can avoid one of the extra save/restore operations of > >HCR_EL2 in the world switch code, and we can also soon get rid of the > >other one. > > > >This is safe, because even though the IMO and FMO bits control both > >taking the interrupts to EL2 and remapping ICC_*_EL1 to ICV_*_EL1 > >executed at EL1, as long as we ensure that these bits are clear when > >running the EL1 host, as defined in the HCR_HOST_[VHE_]FLAGS, we're OK. > > NIT: I was a bit confused by the end of the sentence because HCR_HOST_FLAGS > define does not seem to exist. > True, that was nonsense. I have reworded it slightly. Thanks, -Christoffer
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 715d395ef45b..656deeb17bf2 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -79,9 +79,9 @@ */ #define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \ HCR_TVM | HCR_BSU_IS | HCR_FB | HCR_TAC | \ - HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW) + HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | \ + HCR_FMO | HCR_IMO) #define HCR_VIRT_EXCP_MASK (HCR_VSE | HCR_VI | HCR_VF) -#define HCR_INT_OVERRIDE (HCR_FMO | HCR_IMO) #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) /* TCR_EL2 Registers bits */ diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 71700ecee308..f6189d08753e 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -167,8 +167,6 @@ static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu) __vgic_v3_save_state(vcpu); else __vgic_v2_save_state(vcpu); - - write_sysreg(read_sysreg(hcr_el2) & ~HCR_INT_OVERRIDE, hcr_el2); } static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu) @@ -176,7 +174,6 @@ static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu) u64 val; val = read_sysreg(hcr_el2); - val |= HCR_INT_OVERRIDE; val |= vcpu->arch.irq_lines; write_sysreg(val, hcr_el2);