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

commit b856a59141b1066d3c896a0d0231f84dabd040af upstream.

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 <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index 0fa90c962ac831329df43a156c5b0583732099ac..853e2becad18e9abef52b8df3d3d39d09f9ae029 100644 (file)
--- 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
index 01c0511709e3c801030a41311924e4368d8f6007..e2ae91dbde84370b30141cd8489c56d4e50738c1 100644 (file)
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -676,6 +676,8 @@ 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
index b23a59c1c52255cc808d4fbaff6ffb3be2a5abb7..2786eae10c0d4aec26b0c810ddd9b3ca42b9a8dd 100644 (file)
--- 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
index dd8ecfc3f9952fbf86e5d3dd69012ca9ab9a8385..681cb908010047aa320e4fb0ab5cf2307ec318b1 100644 (file)
--- 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
index 60b5c31f3c10e58e72029d8854f13f527d84a097..3e610f60f0314ea69391df8862cc1e24bd6382b3 100644 (file)
--- 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;
 }