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| author | Christoffer Dall <christoffer.dall@linaro.org> | 2017-10-10 22:54:57 +0200 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2018-03-19 10:53:16 +0000 |
| commit | 0c389d90ebf6ff68f9e19cbb32543084d775d351 (patch) | |
| tree | 12f33b965024dbc3e137b392e2ab13bc1fb54027 /arch | |
| parent | 4cdecaba0146481f1503a645b8a5a41c1e8566c9 (diff) | |
| download | linux-0c389d90ebf6ff68f9e19cbb32543084d775d351.tar.bz2 | |
KVM: arm64: Don't save the host ELR_EL2 and SPSR_EL2 on VHE systems
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 on VHE ELR_EL2 and SPSR_EL2 are not useful because we
never enter a guest as a result of an exception entry that would be directly
handled by KVM. The kernel entry code already saves ELR_EL1/SPSR_EL1 on
exception entry, which is enough. Therefore, factor out these registers into
separate save/restore functions, making it easy to exclude them from the VHE
world-switch path later on.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kvm/hyp/sysreg-sr.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index d35b3aa680ab..906606dc4e2c 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -71,6 +71,10 @@ 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); @@ -83,6 +87,7 @@ 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) @@ -96,6 +101,7 @@ 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) @@ -140,6 +146,11 @@ 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); @@ -152,6 +163,7 @@ 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) @@ -165,6 +177,7 @@ 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); } void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu) |