[RFC PATCH 2/3] ARM/ARM64: KVM: Add support for PSCI v0.2 emulation
Christoffer Dall
christoffer.dall at linaro.org
Tue Jan 28 16:04:10 EST 2014
On Tue, Jan 21, 2014 at 06:31:40PM +0530, Anup Patel wrote:
> Currently, the in-kernel PSCI emulation provides PSCI v0.1 interface to
> VCPUs. This patch extends current in-kernel PSCI emulation to provide
> PSCI v0.2 interface to VCPUs.
>
> By default, ARM/ARM64 KVM will always provide PSCI v0.1 interface for
> keeping the ABI backward-compatible.
>
> To select PSCI v0.2 interface for VCPUs, the user space (i.e. QEMU or
> KVMTOOL) will have to set KVM_ARM_VCPU_PSCI_0_2 feature when doing VCPU
> init using KVM_ARM_VCPU_INIT ioctl.
>
> Signed-off-by: Anup Patel <anup.patel at linaro.org>
> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar at linaro.org>
> ---
> arch/arm/include/asm/kvm_host.h | 2 +-
> arch/arm/include/uapi/asm/kvm.h | 39 ++++++++++++++++--
> arch/arm/kvm/arm.c | 6 ++-
> arch/arm/kvm/psci.c | 79 ++++++++++++++++++++++++++++++-------
> arch/arm64/include/asm/kvm_host.h | 2 +-
> arch/arm64/include/uapi/asm/kvm.h | 39 ++++++++++++++++--
> 6 files changed, 143 insertions(+), 24 deletions(-)
>
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index 8a6f6db..0239ac5 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -36,7 +36,7 @@
> #define KVM_COALESCED_MMIO_PAGE_OFFSET 1
> #define KVM_HAVE_ONE_REG
>
> -#define KVM_VCPU_MAX_FEATURES 1
> +#define KVM_VCPU_MAX_FEATURES 2
>
> #include <kvm/arm_vgic.h>
>
> diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
> index c498b60..d9eb74c 100644
> --- a/arch/arm/include/uapi/asm/kvm.h
> +++ b/arch/arm/include/uapi/asm/kvm.h
> @@ -83,6 +83,7 @@ struct kvm_regs {
> #define KVM_VGIC_V2_CPU_SIZE 0x2000
>
> #define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF state */
> +#define KVM_ARM_VCPU_PSCI_0_2 1 /* CPU uses PSCI v0.2 */
>
> struct kvm_vcpu_init {
> __u32 target;
> @@ -164,7 +165,7 @@ struct kvm_arch_memory_slot {
> /* Highest supported SPI, from VGIC_NR_IRQS */
> #define KVM_ARM_IRQ_GIC_MAX 127
>
> -/* PSCI interface */
> +/* PSCI v0.1 interface */
> #define KVM_PSCI_FN_BASE 0x95c1ba5e
> #define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n))
>
> @@ -173,9 +174,41 @@ struct kvm_arch_memory_slot {
> #define KVM_PSCI_FN_CPU_ON KVM_PSCI_FN(2)
> #define KVM_PSCI_FN_MIGRATE KVM_PSCI_FN(3)
>
> +/* PSCI v0.2 interface */
> +#define KVM_PSCI_0_2_FN_BASE 0x84000000
> +#define KVM_PSCI_0_2_FN(n) (KVM_PSCI_0_2_FN_BASE + (n))
> +#define KVM_PSCI_0_2_FN64_BASE 0xC4000000
> +#define KVM_PSCI_0_2_FN64(n) (KVM_PSCI_0_2_FN64_BASE + (n))
> +
> +#define KVM_PSCI_0_2_FN_PSCI_VERSION KVM_PSCI_0_2_FN(0)
> +#define KVM_PSCI_0_2_FN_CPU_SUSPEND KVM_PSCI_0_2_FN(1)
> +#define KVM_PSCI_0_2_FN_CPU_OFF KVM_PSCI_0_2_FN(2)
> +#define KVM_PSCI_0_2_FN_CPU_ON KVM_PSCI_0_2_FN(3)
> +#define KVM_PSCI_0_2_FN_AFFINITY_INFO KVM_PSCI_0_2_FN(4)
> +#define KVM_PSCI_0_2_FN_MIGRATE KVM_PSCI_0_2_FN(5)
> +#define KVM_PSCI_0_2_FN_MIGRATE_INFO_TYPE \
> + KVM_PSCI_0_2_FN(6)
> +#define KVM_PSCI_0_2_FN_MIGRATE_INFO_UP_CPU \
> + KVM_PSCI_0_2_FN(7)
> +#define KVM_PSCI_0_2_FN_SYSTEM_OFF KVM_PSCI_0_2_FN(8)
> +#define KVM_PSCI_0_2_FN_SYSTEM_RESET KVM_PSCI_0_2_FN(9)
> +
> +#define KVM_PSCI_0_2_FN64_CPU_SUSPEND KVM_PSCI_0_2_FN64(1)
> +#define KVM_PSCI_0_2_FN64_CPU_ON KVM_PSCI_0_2_FN64(3)
> +#define KVM_PSCI_0_2_FN64_AFFINITY_INFO KVM_PSCI_0_2_FN64(4)
> +#define KVM_PSCI_0_2_FN64_MIGRATE KVM_PSCI_0_2_FN64(5)
> +#define KVM_PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU \
> + KVM_PSCI_0_2_FN64(7)
> +
> +/* PSCI return values */
> #define KVM_PSCI_RET_SUCCESS 0
> -#define KVM_PSCI_RET_NI ((unsigned long)-1)
> -#define KVM_PSCI_RET_INVAL ((unsigned long)-2)
> +#define KVM_PSCI_RET_NOT_SUPPORTED ((unsigned long)-1)
> +#define KVM_PSCI_RET_INVALID_PARAMS ((unsigned long)-2)
> #define KVM_PSCI_RET_DENIED ((unsigned long)-3)
> +#define KVM_PSCI_RET_ALREADY_ON ((unsigned long)-4)
> +#define KVM_PSCI_RET_ON_PENDING ((unsigned long)-5)
> +#define KVM_PSCI_RET_INTERNAL_FAILURE ((unsigned long)-6)
> +#define KVM_PSCI_RET_NOT_PRESENT ((unsigned long)-7)
> +#define KVM_PSCI_RET_DISABLED ((unsigned long)-8)
>
> #endif /* __ARM_KVM_H__ */
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 2a700e0..0b7817a 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -193,6 +193,7 @@ int kvm_dev_ioctl_check_extension(long ext)
> case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
> case KVM_CAP_ONE_REG:
> case KVM_CAP_ARM_PSCI:
> + case KVM_CAP_ARM_PSCI_0_2:
> r = 1;
> break;
> case KVM_CAP_COALESCED_MMIO:
> @@ -483,7 +484,10 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)
> * PSCI code.
> */
> if (test_and_clear_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features)) {
> - *vcpu_reg(vcpu, 0) = KVM_PSCI_FN_CPU_OFF;
> + if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
> + *vcpu_reg(vcpu, 0) = KVM_PSCI_0_2_FN_CPU_OFF;
> + else
> + *vcpu_reg(vcpu, 0) = KVM_PSCI_FN_CPU_OFF;
> kvm_psci_call(vcpu);
Which tree does this patch apply to? It looks like you'll get a
conflict with:
478a823 arm: KVM: Don't return PSCI_INVAL if waitqueue is inactive
> }
>
> diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
> index 0881bf1..ee044a3 100644
> --- a/arch/arm/kvm/psci.c
> +++ b/arch/arm/kvm/psci.c
> @@ -55,13 +55,13 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> }
>
> if (!vcpu)
> - return KVM_PSCI_RET_INVAL;
> + return KVM_PSCI_RET_INVALID_PARAMS;
>
> target_pc = *vcpu_reg(source_vcpu, 2);
>
> wq = kvm_arch_vcpu_wq(vcpu);
> if (!waitqueue_active(wq))
> - return KVM_PSCI_RET_INVAL;
> + return KVM_PSCI_RET_INVALID_PARAMS;
>
> kvm_reset_vcpu(vcpu);
>
> @@ -84,17 +84,49 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> return KVM_PSCI_RET_SUCCESS;
> }
>
> -/**
> - * kvm_psci_call - handle PSCI call if r0 value is in range
> - * @vcpu: Pointer to the VCPU struct
> - *
> - * Handle PSCI calls from guests through traps from HVC instructions.
> - * The calling convention is similar to SMC calls to the secure world where
> - * the function number is placed in r0 and this function returns true if the
> - * function number specified in r0 is withing the PSCI range, and false
> - * otherwise.
> - */
> -bool kvm_psci_call(struct kvm_vcpu *vcpu)
> +static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
> +{
> + unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
> + unsigned long val;
> +
> + switch (psci_fn) {
> + case KVM_PSCI_0_2_FN_PSCI_VERSION:
> + /*
> + * Bits[31:16] = Major Version = 0
> + * Bits[15:0] = Minor Version = 2
> + */
> + val = 2;
> + break;
> + case KVM_PSCI_0_2_FN_CPU_OFF:
> + kvm_psci_vcpu_off(vcpu);
> + val = KVM_PSCI_RET_SUCCESS;
> + break;
> + case KVM_PSCI_0_2_FN_CPU_ON:
> + case KVM_PSCI_0_2_FN64_CPU_ON:
> + val = kvm_psci_vcpu_on(vcpu);
> + break;
> + case KVM_PSCI_0_2_FN_CPU_SUSPEND:
> + case KVM_PSCI_0_2_FN_AFFINITY_INFO:
> + case KVM_PSCI_0_2_FN_MIGRATE:
> + case KVM_PSCI_0_2_FN_MIGRATE_INFO_TYPE:
> + case KVM_PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
> + case KVM_PSCI_0_2_FN_SYSTEM_OFF:
> + case KVM_PSCI_0_2_FN_SYSTEM_RESET:
> + case KVM_PSCI_0_2_FN64_CPU_SUSPEND:
> + case KVM_PSCI_0_2_FN64_AFFINITY_INFO:
> + case KVM_PSCI_0_2_FN64_MIGRATE:
> + case KVM_PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
> + val = KVM_PSCI_RET_NOT_SUPPORTED;
> + break;
> + default:
> + return false;
> + }
> +
> + *vcpu_reg(vcpu, 0) = val;
> + return true;
> +}
> +
> +static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
> {
> unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
> unsigned long val;
> @@ -109,9 +141,8 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu)
> break;
> case KVM_PSCI_FN_CPU_SUSPEND:
> case KVM_PSCI_FN_MIGRATE:
> - val = KVM_PSCI_RET_NI;
> + val = KVM_PSCI_RET_NOT_SUPPORTED;
> break;
> -
> default:
> return false;
> }
> @@ -119,3 +150,21 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu)
> *vcpu_reg(vcpu, 0) = val;
> return true;
> }
> +
> +/**
> + * kvm_psci_call - handle PSCI call if r0 value is in range
> + * @vcpu: Pointer to the VCPU struct
> + *
> + * Handle PSCI calls from guests through traps from HVC instructions.
> + * The calling convention is similar to SMC calls to the secure world where
> + * the function number is placed in r0 and this function returns true if the
> + * function number specified in r0 is withing the PSCI range, and false
> + * otherwise.
> + */
> +bool kvm_psci_call(struct kvm_vcpu *vcpu)
> +{
> + if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
> + return kvm_psci_0_2_call(vcpu);
> +
> + return kvm_psci_0_1_call(vcpu);
> +}
Why don't we just try one after the other? Do they conflict in some
way?
I assume PSCI calls are never going to be in the critical path and calls
into PSCI are pretty much expected to be slow as a dog anyhow, so if we
could avoid the extra churn in user space code and potential user
confusion (providing PSCI 0.2 kernel but too old user space tool for
example), I think that would be preferred.
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 0a1d697..92242ce 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -39,7 +39,7 @@
> #include <kvm/arm_vgic.h>
> #include <kvm/arm_arch_timer.h>
>
> -#define KVM_VCPU_MAX_FEATURES 2
> +#define KVM_VCPU_MAX_FEATURES 3
>
> struct kvm_vcpu;
> int kvm_target_cpu(void);
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index d9f026b..0eb254d 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -77,6 +77,7 @@ struct kvm_regs {
>
> #define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF state */
> #define KVM_ARM_VCPU_EL1_32BIT 1 /* CPU running a 32bit VM */
> +#define KVM_ARM_VCPU_PSCI_0_2 2 /* CPU uses PSCI v0.2 */
>
> struct kvm_vcpu_init {
> __u32 target;
> @@ -150,7 +151,7 @@ struct kvm_arch_memory_slot {
> /* Highest supported SPI, from VGIC_NR_IRQS */
> #define KVM_ARM_IRQ_GIC_MAX 127
>
> -/* PSCI interface */
> +/* PSCI v0.1 interface */
> #define KVM_PSCI_FN_BASE 0x95c1ba5e
> #define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n))
>
> @@ -159,10 +160,42 @@ struct kvm_arch_memory_slot {
> #define KVM_PSCI_FN_CPU_ON KVM_PSCI_FN(2)
> #define KVM_PSCI_FN_MIGRATE KVM_PSCI_FN(3)
>
> +/* PSCI v0.2 interface */
> +#define KVM_PSCI_0_2_FN_BASE 0x84000000
> +#define KVM_PSCI_0_2_FN(n) (KVM_PSCI_0_2_FN_BASE + (n))
> +#define KVM_PSCI_0_2_FN64_BASE 0xC4000000
> +#define KVM_PSCI_0_2_FN64(n) (KVM_PSCI_0_2_FN64_BASE + (n))
> +
> +#define KVM_PSCI_0_2_FN_PSCI_VERSION KVM_PSCI_0_2_FN(0)
> +#define KVM_PSCI_0_2_FN_CPU_SUSPEND KVM_PSCI_0_2_FN(1)
> +#define KVM_PSCI_0_2_FN_CPU_OFF KVM_PSCI_0_2_FN(2)
> +#define KVM_PSCI_0_2_FN_CPU_ON KVM_PSCI_0_2_FN(3)
> +#define KVM_PSCI_0_2_FN_AFFINITY_INFO KVM_PSCI_0_2_FN(4)
> +#define KVM_PSCI_0_2_FN_MIGRATE KVM_PSCI_0_2_FN(5)
> +#define KVM_PSCI_0_2_FN_MIGRATE_INFO_TYPE \
> + KVM_PSCI_0_2_FN(6)
> +#define KVM_PSCI_0_2_FN_MIGRATE_INFO_UP_CPU \
> + KVM_PSCI_0_2_FN(7)
> +#define KVM_PSCI_0_2_FN_SYSTEM_OFF KVM_PSCI_0_2_FN(8)
> +#define KVM_PSCI_0_2_FN_SYSTEM_RESET KVM_PSCI_0_2_FN(9)
> +
> +#define KVM_PSCI_0_2_FN64_CPU_SUSPEND KVM_PSCI_0_2_FN64(1)
> +#define KVM_PSCI_0_2_FN64_CPU_ON KVM_PSCI_0_2_FN64(3)
> +#define KVM_PSCI_0_2_FN64_AFFINITY_INFO KVM_PSCI_0_2_FN64(4)
> +#define KVM_PSCI_0_2_FN64_MIGRATE KVM_PSCI_0_2_FN64(5)
> +#define KVM_PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU \
> + KVM_PSCI_0_2_FN64(7)
> +
> +/* PSCI return values */
> #define KVM_PSCI_RET_SUCCESS 0
> -#define KVM_PSCI_RET_NI ((unsigned long)-1)
> -#define KVM_PSCI_RET_INVAL ((unsigned long)-2)
> +#define KVM_PSCI_RET_NOT_SUPPORTED ((unsigned long)-1)
> +#define KVM_PSCI_RET_INVALID_PARAMS ((unsigned long)-2)
> #define KVM_PSCI_RET_DENIED ((unsigned long)-3)
> +#define KVM_PSCI_RET_ALREADY_ON ((unsigned long)-4)
> +#define KVM_PSCI_RET_ON_PENDING ((unsigned long)-5)
> +#define KVM_PSCI_RET_INTERNAL_FAILURE ((unsigned long)-6)
> +#define KVM_PSCI_RET_NOT_PRESENT ((unsigned long)-7)
> +#define KVM_PSCI_RET_DISABLED ((unsigned long)-8)
>
> #endif
>
> --
> 1.7.9.5
>
Thanks,
--
Christoffer
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