| Message ID | 20210825161815.266051-26-alexandru.elisei@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Add Statistical Profiling Extension (SPE) support | expand |
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index e4a2f295a394..5084a54d012e 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -92,7 +92,6 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) write_sysreg(0, pmselr_el0); write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); } - write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); } static inline void __deactivate_traps_common(void) diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index f7af9688c1f7..0c70d897a493 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -41,6 +41,8 @@ static void __activate_traps(struct kvm_vcpu *vcpu) ___activate_traps(vcpu); __activate_traps_common(vcpu); + write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); + val = CPTR_EL2_DEFAULT; val |= CPTR_EL2_TTA | CPTR_EL2_TAM; if (!update_fp_enabled(vcpu)) { diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 86d4c8c33f3e..983ba1570d72 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -89,6 +89,8 @@ NOKPROBE_SYMBOL(__deactivate_traps); void activate_traps_vhe_load(struct kvm_vcpu *vcpu) { __activate_traps_common(vcpu); + + write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); } void deactivate_traps_vhe_put(void)
To run a guest with SPE, MDCR_EL2 must be configured such that the buffer owning regime is EL1&0. With VHE enabled, the guest runs at EL2 and changing the owning regime to EL1&0 too early in vcpu_put() would mean creating an extended blackout window for the host. Move the MDCR_EL2 write out of __activate_traps_common() to prepare for executing it later in the run loop in the VHE case. This also makes __activate_traps_common() look more like __deactivate_traps_common(), which does not touch the register. No functional change intended. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> --- arch/arm64/kvm/hyp/include/hyp/switch.h | 1 - arch/arm64/kvm/hyp/nvhe/switch.c | 2 ++ arch/arm64/kvm/hyp/vhe/switch.c | 2 ++ 3 files changed, 4 insertions(+), 1 deletion(-)