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authorMarc Zyngier <maz@kernel.org>2020-06-05 14:08:13 +0100
committerMarc Zyngier <maz@kernel.org>2020-06-09 10:59:52 +0100
commit07da1ffaa1373f99331712faa67a00b5b807dfe8 (patch)
treec3c5e732314aabf8e6e3a33abdcd05fe99048cd6 /arch/arm64/kvm
parentb990d37fdf6781fd0907ffd14d0dff16b5d58ffa (diff)
downloadlinux-07da1ffaa1373f99331712faa67a00b5b807dfe8.tar.bz2
KVM: arm64: Remove host_cpu_context member from vcpu structure
For very long, we have kept this pointer back to the per-cpu host state, despite having working per-cpu accessors at EL2 for some time now. Recent investigations have shown that this pointer is easy to abuse in preemptible context, which is a sure sign that it would better be gone. Not to mention that a per-cpu pointer is faster to access at all times. Reported-by: Andrew Scull <ascull@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com Reviewed-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm')
-rw-r--r--arch/arm64/kvm/arm.c3
-rw-r--r--arch/arm64/kvm/hyp/debug-sr.c4
-rw-r--r--arch/arm64/kvm/hyp/switch.c6
-rw-r--r--arch/arm64/kvm/hyp/sysreg-sr.c6
-rw-r--r--arch/arm64/kvm/pmu.c8
5 files changed, 11 insertions, 16 deletions
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 14b747266607..6ddaa23ef346 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -340,10 +340,8 @@ void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
int *last_ran;
- kvm_host_data_t *cpu_data;
last_ran = this_cpu_ptr(vcpu->kvm->arch.last_vcpu_ran);
- cpu_data = this_cpu_ptr(&kvm_host_data);
/*
* We might get preempted before the vCPU actually runs, but
@@ -355,7 +353,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
}
vcpu->cpu = cpu;
- vcpu->arch.host_cpu_context = &cpu_data->host_ctxt;
kvm_vgic_load(vcpu);
kvm_timer_vcpu_load(vcpu);
diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c
index 0fc9872a1467..e95af204fec7 100644
--- a/arch/arm64/kvm/hyp/debug-sr.c
+++ b/arch/arm64/kvm/hyp/debug-sr.c
@@ -185,7 +185,7 @@ void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu)
if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
return;
- host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+ host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
guest_ctxt = &vcpu->arch.ctxt;
host_dbg = &vcpu->arch.host_debug_state.regs;
guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
@@ -207,7 +207,7 @@ void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu)
if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
return;
- host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+ host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
guest_ctxt = &vcpu->arch.ctxt;
host_dbg = &vcpu->arch.host_debug_state.regs;
guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index d60c2ef0fe8c..1853c1788e0c 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -532,7 +532,7 @@ static bool __hyp_text __hyp_handle_ptrauth(struct kvm_vcpu *vcpu)
!esr_is_ptrauth_trap(kvm_vcpu_get_hsr(vcpu)))
return false;
- ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+ ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
__ptrauth_save_key(ctxt->sys_regs, APIA);
__ptrauth_save_key(ctxt->sys_regs, APIB);
__ptrauth_save_key(ctxt->sys_regs, APDA);
@@ -703,7 +703,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
struct kvm_cpu_context *guest_ctxt;
u64 exit_code;
- host_ctxt = vcpu->arch.host_cpu_context;
+ host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
host_ctxt->__hyp_running_vcpu = vcpu;
guest_ctxt = &vcpu->arch.ctxt;
@@ -808,7 +808,7 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
vcpu = kern_hyp_va(vcpu);
- host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+ host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
host_ctxt->__hyp_running_vcpu = vcpu;
guest_ctxt = &vcpu->arch.ctxt;
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 6d2df9fe0b5d..143d7b7358f2 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -265,12 +265,13 @@ void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
*/
void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu)
{
- struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
+ struct kvm_cpu_context *host_ctxt;
if (!has_vhe())
return;
+ host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
__sysreg_save_user_state(host_ctxt);
/*
@@ -301,12 +302,13 @@ void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu)
*/
void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu)
{
- struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
+ struct kvm_cpu_context *host_ctxt;
if (!has_vhe())
return;
+ host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
deactivate_traps_vhe_put();
__sysreg_save_el1_state(guest_ctxt);
diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c
index e71d00bb5271..b5ae3a5d509e 100644
--- a/arch/arm64/kvm/pmu.c
+++ b/arch/arm64/kvm/pmu.c
@@ -163,15 +163,13 @@ static void kvm_vcpu_pmu_disable_el0(unsigned long events)
*/
void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu)
{
- struct kvm_cpu_context *host_ctxt;
struct kvm_host_data *host;
u32 events_guest, events_host;
if (!has_vhe())
return;
- host_ctxt = vcpu->arch.host_cpu_context;
- host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
+ host = this_cpu_ptr(&kvm_host_data);
events_guest = host->pmu_events.events_guest;
events_host = host->pmu_events.events_host;
@@ -184,15 +182,13 @@ void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu)
*/
void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu)
{
- struct kvm_cpu_context *host_ctxt;
struct kvm_host_data *host;
u32 events_guest, events_host;
if (!has_vhe())
return;
- host_ctxt = vcpu->arch.host_cpu_context;
- host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
+ host = this_cpu_ptr(&kvm_host_data);
events_guest = host->pmu_events.events_guest;
events_host = host->pmu_events.events_host;