From: Christoffer Dall <christoffer.dall@linaro.org>
Date: Thu, 22 Dec 2016 20:39:10 +0100
Subject: KVM: arm/arm64: Handle VGICv2 save/restore from the main VGIC code
Patch-mainline: v4.17-rc1
Git-commit: 75174ba6ca9dcfddda88aa420da4d7aa2b279fdf
References: bsc#1085308 CVE-2018-3639
We can program the GICv2 hypervisor control interface logic directly
from the core vgic code and can instead do the save/restore directly
from the flush/sync functions, which can lead to a number of future
optimizations.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Liang Yan <lyan@suse.com>
---
arch/arm/kvm/hyp/switch.c | 4 --
arch/arm64/include/asm/kvm_hyp.h | 2 -
arch/arm64/kvm/hyp/switch.c | 4 --
virt/kvm/arm/vgic/vgic-v2.c | 63 +++++++++++++++++++++++++++++++++++++++
virt/kvm/arm/vgic/vgic.c | 19 +++++++++++
virt/kvm/arm/vgic/vgic.h | 3 +
6 files changed, 84 insertions(+), 11 deletions(-)
--- a/arch/arm/kvm/hyp/switch.c
+++ b/arch/arm/kvm/hyp/switch.c
@@ -92,16 +92,12 @@ static void __hyp_text __vgic_save_state
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_save_state(vcpu);
- else
- __vgic_v2_save_state(vcpu);
}
static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu)
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_restore_state(vcpu);
- else
- __vgic_v2_restore_state(vcpu);
}
static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu)
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -120,8 +120,6 @@ typeof(orig) * __hyp_text fname(void)
return val; \
}
-void __vgic_v2_save_state(struct kvm_vcpu *vcpu);
-void __vgic_v2_restore_state(struct kvm_vcpu *vcpu);
int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu);
void __vgic_v3_save_state(struct kvm_vcpu *vcpu);
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -171,8 +171,6 @@ static void __hyp_text __vgic_save_state
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_save_state(vcpu);
- else
- __vgic_v2_save_state(vcpu);
write_sysreg(read_sysreg(hcr_el2) & ~HCR_INT_OVERRIDE, hcr_el2);
}
@@ -188,8 +186,6 @@ static void __hyp_text __vgic_restore_st
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_restore_state(vcpu);
- else
- __vgic_v2_restore_state(vcpu);
}
static bool __hyp_text __true_value(void)
--- a/virt/kvm/arm/vgic/vgic-v2.c
+++ b/virt/kvm/arm/vgic/vgic-v2.c
@@ -392,6 +392,69 @@ out:
return ret;
}
+static void save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
+{
+ struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+ u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+ u64 elrsr;
+ int i;
+
+ elrsr = readl_relaxed(base + GICH_ELRSR0);
+ if (unlikely(used_lrs > 32))
+ elrsr |= ((u64)readl_relaxed(base + GICH_ELRSR1)) << 32;
+
+ for (i = 0; i < used_lrs; i++) {
+ if (elrsr & (1UL << i))
+ cpu_if->vgic_lr[i] &= ~GICH_LR_STATE;
+ else
+ cpu_if->vgic_lr[i] = readl_relaxed(base + GICH_LR0 + (i * 4));
+
+ writel_relaxed(0, base + GICH_LR0 + (i * 4));
+ }
+}
+
+void vgic_v2_save_state(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct vgic_dist *vgic = &kvm->arch.vgic;
+ struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+ void __iomem *base = vgic->vctrl_base;
+ u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+
+ if (!base)
+ return;
+
+ if (used_lrs) {
+ cpu_if->vgic_apr = readl_relaxed(base + GICH_APR);
+ save_lrs(vcpu, base);
+ writel_relaxed(0, base + GICH_HCR);
+ } else {
+ cpu_if->vgic_apr = 0;
+ }
+}
+
+void vgic_v2_restore_state(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct vgic_dist *vgic = &kvm->arch.vgic;
+ struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+ void __iomem *base = vgic->vctrl_base;
+ u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+ int i;
+
+ if (!base)
+ return;
+
+ if (used_lrs) {
+ writel_relaxed(cpu_if->vgic_hcr, base + GICH_HCR);
+ writel_relaxed(cpu_if->vgic_apr, base + GICH_APR);
+ for (i = 0; i < used_lrs; i++) {
+ writel_relaxed(cpu_if->vgic_lr[i],
+ base + GICH_LR0 + (i * 4));
+ }
+ }
+}
+
void vgic_v2_load(struct kvm_vcpu *vcpu)
{
struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -714,11 +714,19 @@ next:
vgic_clear_lr(vcpu, count);
}
+static inline void vgic_save_state(struct kvm_vcpu *vcpu)
+{
+ if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ vgic_v2_save_state(vcpu);
+}
+
/* Sync back the hardware VGIC state into our emulation after a guest's run. */
void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+ vgic_save_state(vcpu);
+
WARN_ON(vgic_v4_sync_hwstate(vcpu));
/* An empty ap_list_head implies used_lrs == 0 */
@@ -730,6 +738,12 @@ void kvm_vgic_sync_hwstate(struct kvm_vc
vgic_prune_ap_list(vcpu);
}
+static inline void vgic_restore_state(struct kvm_vcpu *vcpu)
+{
+ if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ vgic_v2_restore_state(vcpu);
+}
+
/* Flush our emulation state into the GIC hardware before entering the guest. */
void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
{
@@ -745,13 +759,16 @@ void kvm_vgic_flush_hwstate(struct kvm_v
* this.
*/
if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
- return;
+ goto out;
DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());
spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
vgic_flush_lr_state(vcpu);
spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
+
+out:
+ vgic_restore_state(vcpu);
}
void kvm_vgic_load(struct kvm_vcpu *vcpu)
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -169,6 +169,9 @@ void vgic_v2_init_lrs(void);
void vgic_v2_load(struct kvm_vcpu *vcpu);
void vgic_v2_put(struct kvm_vcpu *vcpu);
+void vgic_v2_save_state(struct kvm_vcpu *vcpu);
+void vgic_v2_restore_state(struct kvm_vcpu *vcpu);
+
static inline void vgic_get_irq_kref(struct vgic_irq *irq)
{
if (irq->intid < VGIC_MIN_LPI)