[PATCH v5 07/40] KVM: arm/arm64: Add kvm_vcpu_load_sysregs and kvm_vcpu_put_sysregs
From: cdall@kernel.org (Christoffer Dall)
Date: 2018-02-27 11:33:56
Also in:
kvm, kvmarm
Subsystem:
arm port, arm64 port (aarch64 architecture), kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Russell King, Catalin Marinas, Will Deacon, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Christoffer Dall <redacted>
As we are about to move a bunch of save/restore logic for VHE kernels to
the load and put functions, we need some infrastructure to do this.
Reviewed-by: Andrew Jones <redacted>
Acked-by: Marc Zyngier <redacted>
Signed-off-by: Christoffer Dall <redacted>
---
Notes:
Changes since v1:
- Reworded comments as suggested by Drew
arch/arm/include/asm/kvm_host.h | 3 +++
arch/arm64/include/asm/kvm_host.h | 3 +++
arch/arm64/kvm/hyp/sysreg-sr.c | 30 ++++++++++++++++++++++++++++++
virt/kvm/arm/arm.c | 2 ++
4 files changed, 38 insertions(+)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 6137195ab815..c6a749568dd6 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h@@ -312,4 +312,7 @@ static inline bool kvm_arm_harden_branch_predictor(void) return false; } +static inline void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu) {} +static inline void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) {} + #endif /* __ARM_KVM_HOST_H__ */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index b027a7f025d4..c30fc96992df 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -435,4 +435,7 @@ static inline bool kvm_arm_harden_branch_predictor(void) return cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR); } +void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu); +void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu); + #endif /* __ARM64_KVM_HOST_H__ */
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 43b7dd65e3e6..434f0fc9cfb3 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c@@ -190,6 +190,36 @@ void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu) write_sysreg(sysreg[DBGVCR32_EL2], dbgvcr32_el2); } +/** + * kvm_vcpu_load_sysregs - Load guest system registers to the physical CPU + * + * @vcpu: The VCPU pointer + * + * Load system registers that do not affect the host's execution, for + * example EL1 system registers on a VHE system where the host kernel + * runs at EL2. This function is called from KVM's vcpu_load() function + * and loading system register state early avoids having to load them on + * every entry to the VM. + */ +void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu) +{ +} + +/** + * kvm_vcpu_put_sysregs - Restore host system registers to the physical CPU + * + * @vcpu: The VCPU pointer + * + * Save guest system registers that do not affect the host's execution, for + * example EL1 system registers on a VHE system where the host kernel + * runs at EL2. This function is called from KVM's vcpu_put() function + * and deferring saving system register state until we're no longer running the + * VCPU avoids having to save them on every exit from the VM. + */ +void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) +{ +} + void __hyp_text __kvm_set_tpidr_el2(u64 tpidr_el2) { asm("msr tpidr_el2, %0": : "r" (tpidr_el2));
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 49d13510e9c2..2062d9357971 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c@@ -362,10 +362,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_arm_set_running_vcpu(vcpu); kvm_vgic_load(vcpu); kvm_timer_vcpu_load(vcpu); + kvm_vcpu_load_sysregs(vcpu); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { + kvm_vcpu_put_sysregs(vcpu); kvm_timer_vcpu_put(vcpu); kvm_vgic_put(vcpu);
--
2.14.2