2020-09-16 20:04:31

by David Brazdil

[permalink] [raw]
Subject: [PATCH v3 08/11] kvm: arm64: Create separate instances of kvm_host_data for VHE/nVHE

Host CPU context is stored in a global per-cpu variable `kvm_host_data`.
In preparation for introducing independent per-CPU region for nVHE hyp,
create two separate instances of `kvm_host_data`, one for VHE and one
for nVHE.

Signed-off-by: David Brazdil <[email protected]>
---
arch/arm64/include/asm/kvm_host.h | 2 +-
arch/arm64/kernel/image-vars.h | 1 -
arch/arm64/kvm/arm.c | 5 ++---
arch/arm64/kvm/hyp/nvhe/switch.c | 3 +++
arch/arm64/kvm/hyp/vhe/switch.c | 3 +++
arch/arm64/kvm/pmu.c | 8 ++++----
6 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 905c2b87e05a..5d8c63f5e97e 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -565,7 +565,7 @@ void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 syndrome);

struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);

-DECLARE_PER_CPU(kvm_host_data_t, kvm_host_data);
+DECLARE_KVM_HYP_PER_CPU(kvm_host_data_t, kvm_host_data);

static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt)
{
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 59d12a0b4622..80da861b8180 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -67,7 +67,6 @@ KVM_NVHE_ALIAS(kvm_patch_vector_branch);
KVM_NVHE_ALIAS(kvm_update_va_mask);

/* Global kernel state accessed by nVHE hyp code. */
-KVM_NVHE_ALIAS(kvm_host_data);
KVM_NVHE_ALIAS(kvm_vgic_global_state);

/* Kernel constant needed to compute idmap addresses. */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 3bdc2661d276..7af9809fa193 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -46,7 +46,6 @@
__asm__(".arch_extension virt");
#endif

-DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data);
static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);

/* The VMID used in the VTTBR */
@@ -1308,7 +1307,7 @@ static void cpu_hyp_reset(void)

static void cpu_hyp_reinit(void)
{
- kvm_init_host_cpu_context(&this_cpu_ptr(&kvm_host_data)->host_ctxt);
+ kvm_init_host_cpu_context(&this_cpu_ptr_hyp(kvm_host_data)->host_ctxt);

cpu_hyp_reset();

@@ -1543,7 +1542,7 @@ static int init_hyp_mode(void)
for_each_possible_cpu(cpu) {
kvm_host_data_t *cpu_data;

- cpu_data = per_cpu_ptr(&kvm_host_data, cpu);
+ cpu_data = per_cpu_ptr_hyp(kvm_host_data, cpu);
err = create_hyp_mappings(cpu_data, cpu_data + 1, PAGE_HYP);

if (err) {
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 4662df6330d7..a7e9b03bd9d1 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -30,6 +30,9 @@
/* Non-VHE copy of the kernel symbol. */
DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);

+/* Non-VHE instance of kvm_host_data. */
+DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data);
+
static void __activate_traps(struct kvm_vcpu *vcpu)
{
u64 val;
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 575e8054f116..0949fc97bf03 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -28,6 +28,9 @@

const char __hyp_panic_string[] = "HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n";

+/* VHE instance of kvm_host_data. */
+DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data);
+
static void __activate_traps(struct kvm_vcpu *vcpu)
{
u64 val;
diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c
index 3c224162b3dd..6d80ffe1ebfc 100644
--- a/arch/arm64/kvm/pmu.c
+++ b/arch/arm64/kvm/pmu.c
@@ -31,7 +31,7 @@ static bool kvm_pmu_switch_needed(struct perf_event_attr *attr)
*/
void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr)
{
- struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data);
+ struct kvm_host_data *ctx = this_cpu_ptr_hyp(kvm_host_data);

if (!kvm_pmu_switch_needed(attr))
return;
@@ -47,7 +47,7 @@ void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr)
*/
void kvm_clr_pmu_events(u32 clr)
{
- struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data);
+ struct kvm_host_data *ctx = this_cpu_ptr_hyp(kvm_host_data);

ctx->pmu_events.events_host &= ~clr;
ctx->pmu_events.events_guest &= ~clr;
@@ -173,7 +173,7 @@ void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu)
return;

preempt_disable();
- host = this_cpu_ptr(&kvm_host_data);
+ host = this_cpu_ptr_hyp(kvm_host_data);
events_guest = host->pmu_events.events_guest;
events_host = host->pmu_events.events_host;

@@ -193,7 +193,7 @@ void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu)
if (!has_vhe())
return;

- host = this_cpu_ptr(&kvm_host_data);
+ host = this_cpu_ptr_hyp(kvm_host_data);
events_guest = host->pmu_events.events_guest;
events_host = host->pmu_events.events_host;

--
2.28.0.618.gf4bc123cb7-goog


2020-09-18 12:02:05

by Will Deacon

[permalink] [raw]
Subject: Re: [PATCH v3 08/11] kvm: arm64: Create separate instances of kvm_host_data for VHE/nVHE

On Wed, Sep 16, 2020 at 06:34:36PM +0100, David Brazdil wrote:
> Host CPU context is stored in a global per-cpu variable `kvm_host_data`.
> In preparation for introducing independent per-CPU region for nVHE hyp,
> create two separate instances of `kvm_host_data`, one for VHE and one
> for nVHE.
>
> Signed-off-by: David Brazdil <[email protected]>
> ---
> arch/arm64/include/asm/kvm_host.h | 2 +-
> arch/arm64/kernel/image-vars.h | 1 -
> arch/arm64/kvm/arm.c | 5 ++---
> arch/arm64/kvm/hyp/nvhe/switch.c | 3 +++
> arch/arm64/kvm/hyp/vhe/switch.c | 3 +++
> arch/arm64/kvm/pmu.c | 8 ++++----
> 6 files changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 905c2b87e05a..5d8c63f5e97e 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -565,7 +565,7 @@ void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 syndrome);
>
> struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
>
> -DECLARE_PER_CPU(kvm_host_data_t, kvm_host_data);
> +DECLARE_KVM_HYP_PER_CPU(kvm_host_data_t, kvm_host_data);
>
> static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt)
> {
> diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
> index 59d12a0b4622..80da861b8180 100644
> --- a/arch/arm64/kernel/image-vars.h
> +++ b/arch/arm64/kernel/image-vars.h
> @@ -67,7 +67,6 @@ KVM_NVHE_ALIAS(kvm_patch_vector_branch);
> KVM_NVHE_ALIAS(kvm_update_va_mask);
>
> /* Global kernel state accessed by nVHE hyp code. */
> -KVM_NVHE_ALIAS(kvm_host_data);
> KVM_NVHE_ALIAS(kvm_vgic_global_state);
>
> /* Kernel constant needed to compute idmap addresses. */
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 3bdc2661d276..7af9809fa193 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -46,7 +46,6 @@
> __asm__(".arch_extension virt");
> #endif
>
> -DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data);
> static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
>
> /* The VMID used in the VTTBR */
> @@ -1308,7 +1307,7 @@ static void cpu_hyp_reset(void)
>
> static void cpu_hyp_reinit(void)
> {
> - kvm_init_host_cpu_context(&this_cpu_ptr(&kvm_host_data)->host_ctxt);
> + kvm_init_host_cpu_context(&this_cpu_ptr_hyp(kvm_host_data)->host_ctxt);
>
> cpu_hyp_reset();
>
> @@ -1543,7 +1542,7 @@ static int init_hyp_mode(void)
> for_each_possible_cpu(cpu) {
> kvm_host_data_t *cpu_data;
>
> - cpu_data = per_cpu_ptr(&kvm_host_data, cpu);
> + cpu_data = per_cpu_ptr_hyp(kvm_host_data, cpu);

I stand by my earlier comment to add _sym here, given that the ampersand
gets dropped from the argument.

So assuming you do that in the earlier patch:

Acked-by: Will Deacon <[email protected]>

Will