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authorMarc Zyngier <marc.zyngier@arm.com>2017-06-09 14:49:55 +0300
committerMarc Zyngier <marc.zyngier@arm.com>2017-06-15 11:45:06 +0300
commite7f1d1eef482150a64a6e6ad8faf40f8f97eed67 (patch)
tree775d0180010de525234429766897b116b09ef769
parent2873b5082c5fbe2037f12e8d2abc8ad8f8d82a1b (diff)
downloadlinux-e7f1d1eef482150a64a6e6ad8faf40f8f97eed67.tar.xz
KVM: arm64: Log an error if trapping a read-from-write-only GICv3 access
A read-from-write-only GICv3 access should UNDEF at EL1. But since we're in complete paranoia-land with broken CPUs, let's assume the worse and gracefully handle the case. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
-rw-r--r--arch/arm64/kvm/sys_regs.c12
-rw-r--r--virt/kvm/arm/hyp/vgic-v3-sr.c4
2 files changed, 12 insertions, 4 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0fe27024a2e1..8d51c075966d 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -56,7 +56,8 @@
*/
static bool read_from_write_only(struct kvm_vcpu *vcpu,
- const struct sys_reg_params *params)
+ struct sys_reg_params *params,
+ const struct sys_reg_desc *r)
{
WARN_ONCE(1, "Unexpected sys_reg read to write-only register\n");
print_sys_reg_instr(params);
@@ -93,7 +94,7 @@ static bool access_dcsw(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *r)
{
if (!p->is_write)
- return read_from_write_only(vcpu, p);
+ return read_from_write_only(vcpu, p, r);
kvm_set_way_flush(vcpu);
return true;
@@ -135,7 +136,7 @@ static bool access_gic_sgi(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *r)
{
if (!p->is_write)
- return read_from_write_only(vcpu, p);
+ return read_from_write_only(vcpu, p, r);
vgic_v3_dispatch_sgi(vcpu, p->regval);
@@ -773,7 +774,7 @@ static bool access_pmswinc(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
return trap_raz_wi(vcpu, p, r);
if (!p->is_write)
- return read_from_write_only(vcpu, p);
+ return read_from_write_only(vcpu, p, r);
if (pmu_write_swinc_el0_disabled(vcpu))
return false;
@@ -953,7 +954,10 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_VBAR_EL1), NULL, reset_val, VBAR_EL1, 0 },
+ { SYS_DESC(SYS_ICC_EOIR0_EL1), read_from_write_only },
+ { SYS_DESC(SYS_ICC_DIR_EL1), read_from_write_only },
{ SYS_DESC(SYS_ICC_SGI1R_EL1), access_gic_sgi },
+ { SYS_DESC(SYS_ICC_EOIR1_EL1), read_from_write_only },
{ SYS_DESC(SYS_ICC_SRE_EL1), access_gic_sre },
{ SYS_DESC(SYS_CONTEXTIDR_EL1), access_vm_reg, reset_val, CONTEXTIDR_EL1, 0 },
diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
index 15b557697086..b26ce58b012a 100644
--- a/virt/kvm/arm/hyp/vgic-v3-sr.c
+++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
@@ -980,6 +980,8 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
break;
case SYS_ICC_EOIR0_EL1:
case SYS_ICC_EOIR1_EL1:
+ if (unlikely(is_read))
+ return 0;
fn = __vgic_v3_write_eoir;
break;
case SYS_ICC_GRPEN1_EL1:
@@ -1039,6 +1041,8 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
fn = __vgic_v3_write_bpr0;
break;
case SYS_ICC_DIR_EL1:
+ if (unlikely(is_read))
+ return 0;
fn = __vgic_v3_write_dir;
break;
case SYS_ICC_RPR_EL1: