Re: [RFC v1 08/25] target/arm/kvm: Use kvm_vm_check_extension() where necessary

2026-07-16 Thread Mathieu Poirier 
On Mon, Jul 13, 2026 at 10:43:37AM +1000, Gavin Shan wrote:
> On 7/8/26 8:42 AM, Mathieu Poirier wrote:
> > From: Jean-Philippe Brucker 
> > 
> > The Arm KVM code can return different values from KVM_CHECK_EXTENSION
> > depending on the VM type. Use kvm_vm_check_extension() where necessary
> > to ensure we get the right response from KVM.
> > 
> > Signed-off-by: Jean-Philippe Brucker 
> > Signed-off-by: Mathieu Poirier 
> > ---
> >   target/arm/kvm.c | 8 
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> 
> I'm putting a note here so that we won't forget. The following changes are 
> needed
> so that capability KVM_CAP_ARM_NISV_TO_USER won't be enabled for realm guest 
> since
> it has been hidden from the realm guest in (v14) host series.
> 
> diff --git a/target/arm/kvm.c b/target/arm/kvm.c
> index 3d5e16a21c..4c52ee7e1b 100644
> --- a/target/arm/kvm.c
> +++ b/target/arm/kvm.c
> @@ -623,7 +623,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>  return -EINVAL;
>  }
> -if (kvm_check_extension(s, KVM_CAP_ARM_NISV_TO_USER)) {
> +if (kvm_vm_check_extension(s, KVM_CAP_ARM_NISV_TO_USER)) {

Addressed.

>  if (kvm_vm_enable_cap(s, KVM_CAP_ARM_NISV_TO_USER, 0)) {
>  error_report("Failed to enable KVM_CAP_ARM_NISV_TO_USER cap");
>  } else {
> 
> > diff --git a/target/arm/kvm.c b/target/arm/kvm.c
> > index 6aa1cd04e484..c69b5310c184 100644
> > --- a/target/arm/kvm.c
> > +++ b/target/arm/kvm.c
> > @@ -328,7 +328,7 @@ static void 
> > kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
> >1 << KVM_ARM_VCPU_PTRAUTH_GENERIC);
> >   }
> > -if (kvm_check_extension(kvm_state, KVM_CAP_ARM_PMU_V3)) {
> > +if (kvm_vm_check_extension(kvm_state, KVM_CAP_ARM_PMU_V3)) {
> >   init.features[0] |= 1 << KVM_ARM_VCPU_PMU_V3;
> >   pmu_supported = true;
> >   features |= 1ULL << ARM_FEATURE_PMU;
> > @@ -654,11 +654,11 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
> >   }
> >   }
> > -max_hw_wps = kvm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_WPS);
> > +max_hw_wps = kvm_vm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_WPS);
> >   hw_watchpoints = g_array_sized_new(true, true,
> >  sizeof(HWWatchpoint), max_hw_wps);
> > -max_hw_bps = kvm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_BPS);
> > +max_hw_bps = kvm_vm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_BPS);
> >   hw_breakpoints = g_array_sized_new(true, true,
> >  sizeof(HWBreakpoint), max_hw_bps);
> > @@ -1905,7 +1905,7 @@ void kvm_arm_pvtime_init(ARMCPU *cpu, uint64_t ipa)
> >   void kvm_arm_steal_time_finalize(ARMCPU *cpu, Error **errp)
> >   {
> > -bool has_steal_time = kvm_check_extension(kvm_state, 
> > KVM_CAP_STEAL_TIME);
> > +bool has_steal_time = kvm_vm_check_extension(kvm_state, 
> > KVM_CAP_STEAL_TIME);
> >   if (cpu->kvm_steal_time == ON_OFF_AUTO_AUTO) {
> >   if (!has_steal_time || !arm_feature(&cpu->env, 
> > ARM_FEATURE_AARCH64)) {
>

Re: [RFC v1 08/25] target/arm/kvm: Use kvm_vm_check_extension() where necessary

2026-07-12 Thread Gavin Shan 

On 7/8/26 8:42 AM, Mathieu Poirier wrote:

From: Jean-Philippe Brucker 

The Arm KVM code can return different values from KVM_CHECK_EXTENSION
depending on the VM type. Use kvm_vm_check_extension() where necessary
to ensure we get the right response from KVM.

Signed-off-by: Jean-Philippe Brucker 
Signed-off-by: Mathieu Poirier 
---
  target/arm/kvm.c | 8 
  1 file changed, 4 insertions(+), 4 deletions(-)



I'm putting a note here so that we won't forget. The following changes are 
needed
so that capability KVM_CAP_ARM_NISV_TO_USER won't be enabled for realm guest 
since
it has been hidden from the realm guest in (v14) host series.

diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 3d5e16a21c..4c52ee7e1b 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -623,7 +623,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
 return -EINVAL;
 }
 
-if (kvm_check_extension(s, KVM_CAP_ARM_NISV_TO_USER)) {

+if (kvm_vm_check_extension(s, KVM_CAP_ARM_NISV_TO_USER)) {
 if (kvm_vm_enable_cap(s, KVM_CAP_ARM_NISV_TO_USER, 0)) {
 error_report("Failed to enable KVM_CAP_ARM_NISV_TO_USER cap");
 } else {


diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 6aa1cd04e484..c69b5310c184 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -328,7 +328,7 @@ static void 
kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
   1 << KVM_ARM_VCPU_PTRAUTH_GENERIC);
  }
  
-if (kvm_check_extension(kvm_state, KVM_CAP_ARM_PMU_V3)) {

+if (kvm_vm_check_extension(kvm_state, KVM_CAP_ARM_PMU_V3)) {
  init.features[0] |= 1 << KVM_ARM_VCPU_PMU_V3;
  pmu_supported = true;
  features |= 1ULL << ARM_FEATURE_PMU;
@@ -654,11 +654,11 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
  }
  }
  
-max_hw_wps = kvm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_WPS);

+max_hw_wps = kvm_vm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_WPS);
  hw_watchpoints = g_array_sized_new(true, true,
 sizeof(HWWatchpoint), max_hw_wps);
  
-max_hw_bps = kvm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_BPS);

+max_hw_bps = kvm_vm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_BPS);
  hw_breakpoints = g_array_sized_new(true, true,
 sizeof(HWBreakpoint), max_hw_bps);
  
@@ -1905,7 +1905,7 @@ void kvm_arm_pvtime_init(ARMCPU *cpu, uint64_t ipa)
  
  void kvm_arm_steal_time_finalize(ARMCPU *cpu, Error **errp)

  {
-bool has_steal_time = kvm_check_extension(kvm_state, KVM_CAP_STEAL_TIME);
+bool has_steal_time = kvm_vm_check_extension(kvm_state, 
KVM_CAP_STEAL_TIME);
  
  if (cpu->kvm_steal_time == ON_OFF_AUTO_AUTO) {

  if (!has_steal_time || !arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {

[RFC v1 08/25] target/arm/kvm: Use kvm_vm_check_extension() where necessary

2026-07-07 Thread Mathieu Poirier 
From: Jean-Philippe Brucker 

The Arm KVM code can return different values from KVM_CHECK_EXTENSION
depending on the VM type. Use kvm_vm_check_extension() where necessary
to ensure we get the right response from KVM.

Signed-off-by: Jean-Philippe Brucker 
Signed-off-by: Mathieu Poirier 
---
 target/arm/kvm.c | 8 
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 6aa1cd04e484..c69b5310c184 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -328,7 +328,7 @@ static void 
kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
  1 << KVM_ARM_VCPU_PTRAUTH_GENERIC);
 }
 
-if (kvm_check_extension(kvm_state, KVM_CAP_ARM_PMU_V3)) {
+if (kvm_vm_check_extension(kvm_state, KVM_CAP_ARM_PMU_V3)) {
 init.features[0] |= 1 << KVM_ARM_VCPU_PMU_V3;
 pmu_supported = true;
 features |= 1ULL << ARM_FEATURE_PMU;
@@ -654,11 +654,11 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
 }
 }
 
-max_hw_wps = kvm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_WPS);
+max_hw_wps = kvm_vm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_WPS);
 hw_watchpoints = g_array_sized_new(true, true,
sizeof(HWWatchpoint), max_hw_wps);
 
-max_hw_bps = kvm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_BPS);
+max_hw_bps = kvm_vm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_BPS);
 hw_breakpoints = g_array_sized_new(true, true,
sizeof(HWBreakpoint), max_hw_bps);
 
@@ -1905,7 +1905,7 @@ void kvm_arm_pvtime_init(ARMCPU *cpu, uint64_t ipa)
 
 void kvm_arm_steal_time_finalize(ARMCPU *cpu, Error **errp)
 {
-bool has_steal_time = kvm_check_extension(kvm_state, KVM_CAP_STEAL_TIME);
+bool has_steal_time = kvm_vm_check_extension(kvm_state, 
KVM_CAP_STEAL_TIME);
 
 if (cpu->kvm_steal_time == ON_OFF_AUTO_AUTO) {
 if (!has_steal_time || !arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {
-- 
2.43.0