[RFC PATCH v4 25/39] KVM: arm64: Move the write to MDCR_EL2 out of __activate_traps_common()
From: Alexandru Elisei <hidden>
Date: 2021-08-25 16:18:25
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
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 <redacted> --- 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(-)
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)
--
2.33.0
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