Thread (127 messages) 127 messages, 11 authors, 2017-12-06
STALE3108d

[PATCH 24/37] KVM: arm64: Prepare to handle traps on deferred EL0 sysregs

From: Christoffer Dall <hidden>
Date: 2017-10-12 10:41:28
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

We can trap access to ACTLR_EL1 which we can later defer to only
save/restore during vcpu_load and vcpu_put, so let's read the value
directly from the CPU when necessary.

Signed-off-by: Christoffer Dall <redacted>
---
 arch/arm64/kvm/sys_regs_generic_v8.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/sys_regs_generic_v8.c b/arch/arm64/kvm/sys_regs_generic_v8.c
index 969ade1..348f227 100644
--- a/arch/arm64/kvm/sys_regs_generic_v8.c
+++ b/arch/arm64/kvm/sys_regs_generic_v8.c
@@ -38,7 +38,10 @@ static bool access_actlr(struct kvm_vcpu *vcpu,
 	if (p->is_write)
 		return ignore_write(vcpu, p);
 
-	p->regval = vcpu_sys_reg(vcpu, ACTLR_EL1);
+	if (vcpu->arch.sysregs_loaded_on_cpu)
+		read_sysreg(actlr_el1);
+	else
+		p->regval = vcpu_sys_reg(vcpu, ACTLR_EL1);
 	return true;
 }
 
-- 
2.9.0
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