arm/arm64: KVM: Reset the HCR on each vcpu when resetting the vcpu

When userspace resets the vcpu using KVM_ARM_VCPU_INIT, we should also reset the HCR, because we now modify the HCR dynamically to enable/disable trapping of guest accesses to the VM registers. This is crucial for reboot of VMs working since otherwise we will not be doing the necessary cache maintenance operations when faulting in pages with the guest MMU off. Acked-by: Marc Zyngier <[email protected]> Signed-off-by: Christoffer Dall <[email protected]>
torvalds · Dec 13, 2014 · b856a59 · b856a59
1 parent 3ad8b3d
commit b856a59
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Showing 5 changed files with 12 additions and 2 deletions.
diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
@@ -33,6 +33,11 @@ void kvm_inject_undefined(struct kvm_vcpu *vcpu);
 void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr);
 void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr);
 
+static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
+{
+	vcpu->arch.hcr = HCR_GUEST_MASK;
+}
+
 static inline bool vcpu_mode_is_32bit(struct kvm_vcpu *vcpu)
 {
 	return 1;

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
@@ -658,6 +658,8 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
 	if (ret)
 		return ret;
 
+	vcpu_reset_hcr(vcpu);
+
 	/*
 	 * Handle the "start in power-off" case by marking the VCPU as paused.
 	 */

diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
@@ -38,7 +38,6 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 
 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.hcr = HCR_GUEST_MASK;
 	return 0;
 }
 

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
@@ -38,6 +38,11 @@ void kvm_inject_undefined(struct kvm_vcpu *vcpu);
 void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr);
 void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr);
 
+static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
+{
+	vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
+}
+
 static inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
 {
 	return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pc;

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
@@ -38,7 +38,6 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 
 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
 	return 0;
 }
-Original file line number
+Diff line change
@@ Expand Up / @@ -38,7 +38,6 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { @@
     int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
     {
-    	vcpu->arch.hcr = HCR_GUEST_MASK;
     	return 0;
     }
@@ Expand Down @@