[PATCH 21/37] KVM: arm64: Don't save the host ELR_EL2 and SPSR_EL2 on VHE systems
From: Christoffer Dall <hidden>
Date: 2017-10-12 10:41:25
Also in:
kvm, kvmarm
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
On non-VHE systems we need to save the ELR_EL2 and SPSR_EL2 so that we can return to the host in EL1 in the same state and location where we issued a hypercall to EL2, but these registers don't contain anything important on VHE, because all of the host runs in EL2. Therefore, exclude them when saving/restoring the host state. Signed-off-by: Christoffer Dall <redacted> --- arch/arm64/kvm/hyp/sysreg-sr.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index f5c1b44..354ca02 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c@@ -66,6 +66,10 @@ static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1); ctxt->gp_regs.elr_el1 = read_sysreg_el1(elr); ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr); +} + +static void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt) +{ ctxt->gp_regs.regs.pc = read_sysreg_el2(elr); ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr); }
@@ -75,6 +79,7 @@ void __hyp_text __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt) __sysreg_save_el1_state(ctxt); __sysreg_save_common_state(ctxt); __sysreg_save_user_state(ctxt); + __sysreg_save_el2_return_state(ctxt); } void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt)
@@ -88,6 +93,7 @@ void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt) __sysreg_save_el1_state(ctxt); __sysreg_save_common_state(ctxt); __sysreg_save_user_state(ctxt); + __sysreg_save_el2_return_state(ctxt); } static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
@@ -127,6 +133,11 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt) write_sysreg(ctxt->gp_regs.sp_el1, sp_el1); write_sysreg_el1(ctxt->gp_regs.elr_el1, elr); write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr); +} + +static void __hyp_text +__sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt) +{ write_sysreg_el2(ctxt->gp_regs.regs.pc, elr); write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr); }
@@ -136,6 +147,7 @@ void __hyp_text __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt) __sysreg_restore_el1_state(ctxt); __sysreg_restore_common_state(ctxt); __sysreg_restore_user_state(ctxt); + __sysreg_restore_el2_return_state(ctxt); } void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt)
@@ -149,6 +161,7 @@ void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt) __sysreg_restore_el1_state(ctxt); __sysreg_restore_common_state(ctxt); __sysreg_restore_user_state(ctxt); + __sysreg_restore_el2_return_state(ctxt); } static void __hyp_text __fpsimd32_save_state(struct kvm_cpu_context *ctxt)
--
2.9.0