Re: [PATCH v4 02/10] ARM/ARM64: KVM: Add base for PSCI v0.2 emulation

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On Friday, February 07, 2014 5:36 PM, Anup Patel wrote:
> On Fri, Feb 7, 2014 at 1:58 PM, Jungseok Lee <jays.lee@xxxxxxxxxxx> wrote:
> > On Thursday, February 06, 2014 8:32 PM, 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@xxxxxxxxxx>
> >> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@xxxxxxxxxx>
> >> ---
> >>  arch/arm/include/asm/kvm_host.h   |    2 +-
> >>  arch/arm/include/asm/kvm_psci.h   |    4 ++
> >>  arch/arm/include/uapi/asm/kvm.h   |   35 ++++++++++++++-
> >>  arch/arm/kvm/arm.c                |    1 +
> >>  arch/arm/kvm/psci.c               |   85 +++++++++++++++++++++++++++++++------
> >>  arch/arm64/include/asm/kvm_host.h |    2 +-
> >>  arch/arm64/include/asm/kvm_psci.h |    4 ++
> >>  arch/arm64/include/uapi/asm/kvm.h |   35 ++++++++++++++-
> >>  8 files changed, 152 insertions(+), 16 deletions(-)
> >>
> >> diff --git a/arch/arm/include/asm/kvm_host.h
> >> b/arch/arm/include/asm/kvm_host.h index 09af149..193ceaf
> >> 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/asm/kvm_psci.h
> >> b/arch/arm/include/asm/kvm_psci.h index 9a83d98..4c0e3e1
> >> 100644
> >> --- a/arch/arm/include/asm/kvm_psci.h
> >> +++ b/arch/arm/include/asm/kvm_psci.h
> >> @@ -18,6 +18,10 @@
> >>  #ifndef __ARM_KVM_PSCI_H__
> >>  #define __ARM_KVM_PSCI_H__
> >>
> >> +#define KVM_ARM_PSCI_0_1     1
> >> +#define KVM_ARM_PSCI_0_2     2
> >> +
> >> +int kvm_psci_version(struct kvm_vcpu *vcpu);
> >>  bool kvm_psci_call(struct kvm_vcpu *vcpu);
> >>
> >>  #endif /* __ARM_KVM_PSCI_H__ */
> >> diff --git a/arch/arm/include/uapi/asm/kvm.h
> >> b/arch/arm/include/uapi/asm/kvm.h index ef0c878..9c922d9
> >> 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;
> >> @@ -192,7 +193,7 @@ 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))
> >>
> >> @@ -201,9 +202,41 @@ 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)
> >> +
> >
> > Hi
> >
> > This patch describes PSCI v0.2 specification well. Instead, I have a
> > question on interface types, not implementation.
> >
> > According to PSCI v0.2 document, it does not cover DVFS.
> > Could I get an idea why DVFS is not supported?
> 
> PSCI v0.2 only describes few mandatory functions required for being PSCI v0.2 compliant. For rest of
> the stuff such as DVFS you will need to define your own platform specific PSCI function.
> (Marc/Mark correct me if I am wrong here?)

It seems that I should change architecture codes if I need other interfaces.
Under this implementation, I should add my own interface to generic codes,
such as, arch/arm/include/asm/kvm_psci.h. However, I think that it is not
acceptable to upstream. If so, is there any place to define a platform
specific PSCI functions?

Best Regards
Jungseok Lee

> Mab be in future some PSCI vX.Y will define standardized PSCI function for DVFS too.
> 
> Regards,
> Anup
> 
> >
> > Best Regards
> > Jungseok Lee
> >
> >> +/* 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_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
> >> 1d8248e..c8a71df 100644
> >> --- a/arch/arm/kvm/arm.c
> >> +++ b/arch/arm/kvm/arm.c
> >> @@ -197,6 +197,7 @@ 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:
> >> diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index
> >> 448f60e..e4ec4af 100644
> >> --- a/arch/arm/kvm/psci.c
> >> +++ b/arch/arm/kvm/psci.c
> >> @@ -85,17 +85,57 @@ 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)
> >> +int kvm_psci_version(struct kvm_vcpu *vcpu) {
> >> +     if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
> >> +             return KVM_ARM_PSCI_0_2;
> >> +
> >> +     return KVM_ARM_PSCI_0_1;
> >> +}
> >> +
> >> +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_NI;
> >> +             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;
> >> @@ -112,7 +152,6 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu)
> >>       case KVM_PSCI_FN_MIGRATE:
> >>               val = KVM_PSCI_RET_NI;
> >>               break;
> >> -
> >>       default:
> >>               return false;
> >>       }
> >> @@ -120,3 +159,25 @@ 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) {
> >> +     switch (kvm_psci_version(vcpu)) {
> >> +     case KVM_ARM_PSCI_0_2:
> >> +             return kvm_psci_0_2_call(vcpu);
> >> +     case KVM_ARM_PSCI_0_1:
> >> +             return kvm_psci_0_1_call(vcpu);
> >> +     default:
> >> +             return false;
> >> +     };
> >> +}
> >> 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/asm/kvm_psci.h
> >> b/arch/arm64/include/asm/kvm_psci.h
> >> index e301a48..e25c658 100644
> >> --- a/arch/arm64/include/asm/kvm_psci.h
> >> +++ b/arch/arm64/include/asm/kvm_psci.h
> >> @@ -18,6 +18,10 @@
> >>  #ifndef __ARM64_KVM_PSCI_H__
> >>  #define __ARM64_KVM_PSCI_H__
> >>
> >> +#define KVM_ARM_PSCI_0_1     1
> >> +#define KVM_ARM_PSCI_0_2     2
> >> +
> >> +int kvm_psci_version(struct kvm_vcpu *vcpu);
> >>  bool kvm_psci_call(struct kvm_vcpu *vcpu);
> >>
> >>  #endif /* __ARM64_KVM_PSCI_H__ */
> >> diff --git a/arch/arm64/include/uapi/asm/kvm.h
> >> b/arch/arm64/include/uapi/asm/kvm.h
> >> index eaf54a3..cadc318 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;
> >> @@ -177,7 +178,7 @@ 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))
> >>
> >> @@ -186,10 +187,42 @@ 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_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
> >>
> >> _______________________________________________
> >> kvmarm mailing list
> >> kvmarm@xxxxxxxxxxxxxxxxxxxxx
> >> https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
> >
> > _______________________________________________
> > kvmarm mailing list
> > kvmarm@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm


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