Re: [kvmtool PATCH v5 6/6] arm/kvm: arm64: Add a vcpu feature for pointer authentication

2019-01-28 Thread Julien Thierry
Hi Amit,

On 28/01/2019 06:58, Amit Daniel Kachhap wrote:
> This is a runtime feature and can be enabled by --ptrauth option.
> 
> Signed-off-by: Amit Daniel Kachhap 
> Cc: Mark Rutland 
> Cc: Christoffer Dall 
> Cc: Marc Zyngier 
> Cc: Kristina Martsenko 
> Cc: kvm...@lists.cs.columbia.edu
> Cc: Ramana Radhakrishnan 
> Cc: Will Deacon 
> ---
>  arm/aarch32/include/kvm/kvm-cpu-arch.h| 2 ++
>  arm/aarch64/include/asm/kvm.h | 3 +++
>  arm/aarch64/include/kvm/kvm-arch.h| 1 +
>  arm/aarch64/include/kvm/kvm-config-arch.h | 4 +++-
>  arm/aarch64/include/kvm/kvm-cpu-arch.h| 2 ++
>  arm/aarch64/kvm-cpu.c | 5 +
>  arm/include/arm-common/kvm-config-arch.h  | 1 +
>  arm/kvm-cpu.c | 7 +++
>  include/linux/kvm.h   | 1 +
>  9 files changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h 
> b/arm/aarch32/include/kvm/kvm-cpu-arch.h
> index d28ea67..5779767 100644
> --- a/arm/aarch32/include/kvm/kvm-cpu-arch.h
> +++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h
> @@ -13,4 +13,6 @@
>  #define ARM_CPU_ID   0, 0, 0
>  #define ARM_CPU_ID_MPIDR 5
>  
> +unsigned int kvm__cpu_ptrauth_get_feature(void) {}
> +

You probably want a return statement for this function.

>  #endif /* KVM__KVM_CPU_ARCH_H */
> diff --git a/arm/aarch64/include/asm/kvm.h b/arm/aarch64/include/asm/kvm.h
> index c286035..0fd183d 100644
> --- a/arm/aarch64/include/asm/kvm.h
> +++ b/arm/aarch64/include/asm/kvm.h
> @@ -98,6 +98,9 @@ struct kvm_regs {
>  #define KVM_ARM_VCPU_PSCI_0_22 /* CPU uses PSCI v0.2 */
>  #define KVM_ARM_VCPU_PMU_V3  3 /* Support guest PMUv3 */
>  
> +/* CPU uses address authentication and A key */
> +#define KVM_ARM_VCPU_PTRAUTH 4
> +
>  struct kvm_vcpu_init {
>   __u32 target;
>   __u32 features[7];
> diff --git a/arm/aarch64/include/kvm/kvm-arch.h 
> b/arm/aarch64/include/kvm/kvm-arch.h
> index 9de623a..bd566cb 100644
> --- a/arm/aarch64/include/kvm/kvm-arch.h
> +++ b/arm/aarch64/include/kvm/kvm-arch.h
> @@ -11,4 +11,5 @@
>  
>  #include "arm-common/kvm-arch.h"
>  
> +
>  #endif /* KVM__KVM_ARCH_H */
> diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h 
> b/arm/aarch64/include/kvm/kvm-config-arch.h
> index 04be43d..2074684 100644
> --- a/arm/aarch64/include/kvm/kvm-config-arch.h
> +++ b/arm/aarch64/include/kvm/kvm-config-arch.h
> @@ -8,7 +8,9 @@
>   "Create PMUv3 device"), \
>   OPT_U64('\0', "kaslr-seed", &(cfg)->kaslr_seed, \
>   "Specify random seed for Kernel Address Space " \
> - "Layout Randomization (KASLR)"),
> + "Layout Randomization (KASLR)"),\
> + OPT_BOOLEAN('\0', "ptrauth", &(cfg)->has_ptrauth,   \
> + "Enable address authentication"),
>  
>  #include "arm-common/kvm-config-arch.h"
>  
> diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h 
> b/arm/aarch64/include/kvm/kvm-cpu-arch.h
> index a9d8563..f7b64b7 100644
> --- a/arm/aarch64/include/kvm/kvm-cpu-arch.h
> +++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h
> @@ -17,4 +17,6 @@
>  #define ARM_CPU_CTRL 3, 0, 1, 0
>  #define ARM_CPU_CTRL_SCTLR_EL1   0
>  
> +unsigned int kvm__cpu_ptrauth_get_feature(void);
> +>  #endif /* KVM__KVM_CPU_ARCH_H */
> diff --git a/arm/aarch64/kvm-cpu.c b/arm/aarch64/kvm-cpu.c
> index 1b29374..10da2cb 100644
> --- a/arm/aarch64/kvm-cpu.c
> +++ b/arm/aarch64/kvm-cpu.c
> @@ -123,6 +123,11 @@ void kvm_cpu__reset_vcpu(struct kvm_cpu *vcpu)
>   return reset_vcpu_aarch64(vcpu);
>  }
>  
> +unsigned int kvm__cpu_ptrauth_get_feature(void)
> +{
> + return (1UL << KVM_ARM_VCPU_PTRAUTH);
> +}
> +

Couldn't this be a simple:
#define PTRAUTH_FEATURE (1UL << KVM_ARM_VCPU_PTRAUTH)

And just define it to 0 for the aarch32 side?

Cheers,

-- 
Julien Thierry


[kvmtool PATCH v5 6/6] arm/kvm: arm64: Add a vcpu feature for pointer authentication

2019-01-27 Thread Amit Daniel Kachhap
This is a runtime feature and can be enabled by --ptrauth option.

Signed-off-by: Amit Daniel Kachhap 
Cc: Mark Rutland 
Cc: Christoffer Dall 
Cc: Marc Zyngier 
Cc: Kristina Martsenko 
Cc: kvm...@lists.cs.columbia.edu
Cc: Ramana Radhakrishnan 
Cc: Will Deacon 
---
 arm/aarch32/include/kvm/kvm-cpu-arch.h| 2 ++
 arm/aarch64/include/asm/kvm.h | 3 +++
 arm/aarch64/include/kvm/kvm-arch.h| 1 +
 arm/aarch64/include/kvm/kvm-config-arch.h | 4 +++-
 arm/aarch64/include/kvm/kvm-cpu-arch.h| 2 ++
 arm/aarch64/kvm-cpu.c | 5 +
 arm/include/arm-common/kvm-config-arch.h  | 1 +
 arm/kvm-cpu.c | 7 +++
 include/linux/kvm.h   | 1 +
 9 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h 
b/arm/aarch32/include/kvm/kvm-cpu-arch.h
index d28ea67..5779767 100644
--- a/arm/aarch32/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h
@@ -13,4 +13,6 @@
 #define ARM_CPU_ID 0, 0, 0
 #define ARM_CPU_ID_MPIDR   5
 
+unsigned int kvm__cpu_ptrauth_get_feature(void) {}
+
 #endif /* KVM__KVM_CPU_ARCH_H */
diff --git a/arm/aarch64/include/asm/kvm.h b/arm/aarch64/include/asm/kvm.h
index c286035..0fd183d 100644
--- a/arm/aarch64/include/asm/kvm.h
+++ b/arm/aarch64/include/asm/kvm.h
@@ -98,6 +98,9 @@ struct kvm_regs {
 #define KVM_ARM_VCPU_PSCI_0_2  2 /* CPU uses PSCI v0.2 */
 #define KVM_ARM_VCPU_PMU_V33 /* Support guest PMUv3 */
 
+/* CPU uses address authentication and A key */
+#define KVM_ARM_VCPU_PTRAUTH   4
+
 struct kvm_vcpu_init {
__u32 target;
__u32 features[7];
diff --git a/arm/aarch64/include/kvm/kvm-arch.h 
b/arm/aarch64/include/kvm/kvm-arch.h
index 9de623a..bd566cb 100644
--- a/arm/aarch64/include/kvm/kvm-arch.h
+++ b/arm/aarch64/include/kvm/kvm-arch.h
@@ -11,4 +11,5 @@
 
 #include "arm-common/kvm-arch.h"
 
+
 #endif /* KVM__KVM_ARCH_H */
diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h 
b/arm/aarch64/include/kvm/kvm-config-arch.h
index 04be43d..2074684 100644
--- a/arm/aarch64/include/kvm/kvm-config-arch.h
+++ b/arm/aarch64/include/kvm/kvm-config-arch.h
@@ -8,7 +8,9 @@
"Create PMUv3 device"), \
OPT_U64('\0', "kaslr-seed", &(cfg)->kaslr_seed, \
"Specify random seed for Kernel Address Space " \
-   "Layout Randomization (KASLR)"),
+   "Layout Randomization (KASLR)"),\
+   OPT_BOOLEAN('\0', "ptrauth", &(cfg)->has_ptrauth,   \
+   "Enable address authentication"),
 
 #include "arm-common/kvm-config-arch.h"
 
diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h 
b/arm/aarch64/include/kvm/kvm-cpu-arch.h
index a9d8563..f7b64b7 100644
--- a/arm/aarch64/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h
@@ -17,4 +17,6 @@
 #define ARM_CPU_CTRL   3, 0, 1, 0
 #define ARM_CPU_CTRL_SCTLR_EL1 0
 
+unsigned int kvm__cpu_ptrauth_get_feature(void);
+
 #endif /* KVM__KVM_CPU_ARCH_H */
diff --git a/arm/aarch64/kvm-cpu.c b/arm/aarch64/kvm-cpu.c
index 1b29374..10da2cb 100644
--- a/arm/aarch64/kvm-cpu.c
+++ b/arm/aarch64/kvm-cpu.c
@@ -123,6 +123,11 @@ void kvm_cpu__reset_vcpu(struct kvm_cpu *vcpu)
return reset_vcpu_aarch64(vcpu);
 }
 
+unsigned int kvm__cpu_ptrauth_get_feature(void)
+{
+   return (1UL << KVM_ARM_VCPU_PTRAUTH);
+}
+
 int kvm_cpu__get_endianness(struct kvm_cpu *vcpu)
 {
struct kvm_one_reg reg;
diff --git a/arm/include/arm-common/kvm-config-arch.h 
b/arm/include/arm-common/kvm-config-arch.h
index 6a196f1..eb872db 100644
--- a/arm/include/arm-common/kvm-config-arch.h
+++ b/arm/include/arm-common/kvm-config-arch.h
@@ -10,6 +10,7 @@ struct kvm_config_arch {
boolaarch32_guest;
boolhas_pmuv3;
u64 kaslr_seed;
+   boolhas_ptrauth;
enum irqchip_type irqchip;
 };
 
diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c
index 7780251..5afd727 100644
--- a/arm/kvm-cpu.c
+++ b/arm/kvm-cpu.c
@@ -68,6 +68,13 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned 
long cpu_id)
vcpu_init.features[0] |= (1UL << KVM_ARM_VCPU_PSCI_0_2);
}
 
+   /* Set KVM_ARM_VCPU_PTRAUTH_I_A if available */
+   if (kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH)) {
+   if (kvm->cfg.arch.has_ptrauth)
+   vcpu_init.features[0] |=
+   kvm__cpu_ptrauth_get_feature();
+   }
+
/*
 * If the preferred target ioctl is successful then
 * use preferred target else try each and every target type
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index f51d508..204315e 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -883,6 +883,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_PPC_MMU_RADIX