diff mbox series

[v2,03/11] KVM: arm64: switch HCRX_EL2 between host and guest

Message ID 20230509142235.3284028-4-kristina.martsenko@arm.com
State New
Headers
Series arm64: Support for Armv8.8 memcpy instructions in userspace |

Commit Message

Kristina Martsenko May 9, 2023, 2:22 p.m. UTC 
  Switch the HCRX_EL2 register between host and guest configurations, in
order to enable different features in the host and guest.

Now that there are separate guest flags, we can also remove SMPME from
the host flags, as SMPME is used for virtualizing SME priorities and has
no use in the host.

Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
---
 arch/arm64/include/asm/kvm_arm.h        | 3 ++-
 arch/arm64/kvm/hyp/include/hyp/switch.h | 6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

Comments

Catalin Marinas June 2, 2023, 1:51 p.m. UTC | #1 
On Tue, May 09, 2023 at 03:22:27PM +0100, Kristina Martsenko wrote:
> Switch the HCRX_EL2 register between host and guest configurations, in
> order to enable different features in the host and guest.
> 
> Now that there are separate guest flags, we can also remove SMPME from
> the host flags, as SMPME is used for virtualizing SME priorities and has
> no use in the host.
> 
> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>

Same here, it could be good to have Marc/Oliver look at this.
Marc Zyngier June 3, 2023, 8:40 a.m. UTC | #2 
On Tue, 09 May 2023 15:22:27 +0100,
Kristina Martsenko <kristina.martsenko@arm.com> wrote:
> 
> Switch the HCRX_EL2 register between host and guest configurations, in
> order to enable different features in the host and guest.
> 
> Now that there are separate guest flags, we can also remove SMPME from
> the host flags, as SMPME is used for virtualizing SME priorities and has
> no use in the host.
> 
> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>

Acked-by: Marc Zyngier <maz@kernel.org>

	M.
Oliver Upton June 5, 2023, 3:41 p.m. UTC | #3 
On Fri, Jun 02, 2023 at 02:51:53PM +0100, Catalin Marinas wrote:
> On Tue, May 09, 2023 at 03:22:27PM +0100, Kristina Martsenko wrote:
> > Switch the HCRX_EL2 register between host and guest configurations, in
> > order to enable different features in the host and guest.
> > 
> > Now that there are separate guest flags, we can also remove SMPME from
> > the host flags, as SMPME is used for virtualizing SME priorities and has
> > no use in the host.
> > 
> > Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
> 
> Same here, it could be good to have Marc/Oliver look at this.

Acked-by: Oliver Upton <oliver.upton@linux.dev>
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index fb7fe28b8eb8..7bb2fbddda54 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -93,7 +93,8 @@ 
 #define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC)
 #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)
 
-#define HCRX_HOST_FLAGS (HCRX_EL2_SMPME)
+#define HCRX_GUEST_FLAGS (HCRX_EL2_SMPME)
+#define HCRX_HOST_FLAGS 0
 
 /* TCR_EL2 Registers bits */
 #define TCR_EL2_RES1		((1U << 31) | (1 << 23))
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index c41166f1a1dd..8f95bcbe6cdf 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -130,6 +130,9 @@  static inline void ___activate_traps(struct kvm_vcpu *vcpu)
 
 	if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN) && (hcr & HCR_VSE))
 		write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2);
+
+	if (cpus_have_final_cap(ARM64_HAS_HCX))
+		write_sysreg_s(HCRX_GUEST_FLAGS, SYS_HCRX_EL2);
 }
 
 static inline void ___deactivate_traps(struct kvm_vcpu *vcpu)
@@ -144,6 +147,9 @@  static inline void ___deactivate_traps(struct kvm_vcpu *vcpu)
 		vcpu->arch.hcr_el2 &= ~HCR_VSE;
 		vcpu->arch.hcr_el2 |= read_sysreg(hcr_el2) & HCR_VSE;
 	}
+
+	if (cpus_have_final_cap(ARM64_HAS_HCX))
+		write_sysreg_s(HCRX_HOST_FLAGS, SYS_HCRX_EL2);
 }
 
 static inline bool __populate_fault_info(struct kvm_vcpu *vcpu)