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 <christoffer.dall@xxxxxxxxxx>
---
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
