[PATCH v3 10/23] arm64: KVM: VHE: Differenciate host/guest sysreg save/restore

Marc Zyngier
2016-02-03T18:06:41Z

With ARMv8, host and guest share the same system register file,
making the save/restore procedure completely symetrical.
With VHE, host and guest now have different requirements, as they
use different sysregs.

In order to prepare for this, add split sysreg save/restore functions
for both host and guest. No functional changes yet.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kvm/hyp/hyp.h | 6 ++++--
arch/arm64/kvm/hyp/switch.c | 10 +++++-----
arch/arm64/kvm/hyp/sysreg-sr.c | 24 ++++++++++++++++++++++--
3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h
index 744c919..5dfa883 100644
--- a/arch/arm64/kvm/hyp/hyp.h
+++ b/arch/arm64/kvm/hyp/hyp.h
@@ -153,8 +153,10 @@ void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);
void __timer_save_state(struct kvm_vcpu *vcpu);
void __timer_restore_state(struct kvm_vcpu *vcpu);

-void __sysreg_save_state(struct kvm_cpu_context *ctxt);
-void __sysreg_restore_state(struct kvm_cpu_context *ctxt);
+void __sysreg_save_host_state(struct kvm_cpu_context *ctxt);
+void __sysreg_restore_host_state(struct kvm_cpu_context *ctxt);
+void __sysreg_save_guest_state(struct kvm_cpu_context *ctxt);
+void __sysreg_restore_guest_state(struct kvm_cpu_context *ctxt);
void __sysreg32_save_state(struct kvm_vcpu *vcpu);
void __sysreg32_restore_state(struct kvm_vcpu *vcpu);

diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index ca8f5a5..9071dee 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -98,7 +98,7 @@ static int __hyp_text __guest_run(struct kvm_vcpu *vcpu)
host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
guest_ctxt = &vcpu->arch.ctxt;

- __sysreg_save_state(host_ctxt);
+ __sysreg_save_host_state(host_ctxt);
__debug_cond_save_host_state(vcpu);

__activate_traps(vcpu);
@@ -112,7 +112,7 @@ static int __hyp_text __guest_run(struct kvm_vcpu *vcpu)
* to Cortex-A57 erratum #852523.
*/
__sysreg32_restore_state(vcpu);
- __sysreg_restore_state(guest_ctxt);
+ __sysreg_restore_guest_state(guest_ctxt);
__debug_restore_state(vcpu, kern_hyp_va(vcpu->arch.debug_ptr), guest_ctxt);

/* Jump in the fire! */
@@ -121,7 +121,7 @@ static int __hyp_text __guest_run(struct kvm_vcpu *vcpu)

fp_enabled = __fpsimd_enabled();

- __sysreg_save_state(guest_ctxt);
+ __sysreg_save_guest_state(guest_ctxt);
__sysreg32_save_state(vcpu);
__timer_save_state(vcpu);
__vgic_save_state(vcpu);
@@ -129,7 +129,7 @@ static int __hyp_text __guest_run(struct kvm_vcpu *vcpu)
__deactivate_traps(vcpu);
__deactivate_vm(vcpu);

- __sysreg_restore_state(host_ctxt);
+ __sysreg_restore_host_state(host_ctxt);

if (fp_enabled) {
__fpsimd_save_state(&guest_ctxt->gp_regs.fp_regs);
@@ -161,7 +161,7 @@ void __hyp_text __noreturn __hyp_panic(void)
host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
__deactivate_traps(vcpu);
__deactivate_vm(vcpu);
- __sysreg_restore_state(host_ctxt);
+ __sysreg_restore_host_state(host_ctxt);
}

/* Call panic for real */
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 42563098..bd5b543 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -24,7 +24,7 @@
#include "hyp.h"

/* ctxt is already in the HYP VA space */
-void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
+static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
{
ctxt->sys_regs[MPIDR_EL1] = read_sysreg(vmpidr_el2);
ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
@@ -57,7 +57,17 @@ void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg(spsr_el1);
}

-void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
+void __hyp_text __sysreg_save_host_state(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_save_state(ctxt);
+}
+
+void __hyp_text __sysreg_save_guest_state(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_save_state(ctxt);
+}
+
+static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
{
write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2);
write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1);
@@ -90,6 +100,16 @@ void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
write_sysreg(ctxt->gp_regs.spsr[KVM_SPSR_EL1], spsr_el1);
}

+void __hyp_text __sysreg_restore_host_state(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_restore_state(ctxt);
+}
+
+void __hyp_text __sysreg_restore_guest_state(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_restore_state(ctxt);
+}
+
void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
{
u64 *spsr, *sysreg;
--
2.1.4