On 04/27/2018 03:58 PM, Greg Kroah-Hartman wrote:
> 4.9-stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
>
>
> From: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Minus the double author and the unrelated white space change this backport looks good.
>
> [ Upstream commit 35b3fde6203b932b2b1a5b53b3d8808abc9c4f60 ]
>
> The new firmware interfaces for branch prediction behaviour changes
> are transparently available for the guest. Nevertheless, there is
> new state attached that should be migrated and properly resetted.
> Provide a mechanism for handling reset, migration and VSIE.
>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> [Changed capability number to 152. - Radim]
> Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> arch/s390/include/asm/kvm_host.h | 3 ++-
> arch/s390/include/uapi/asm/kvm.h | 5 ++++-
> arch/s390/kvm/kvm-s390.c | 13 ++++++++++++-
> arch/s390/kvm/vsie.c | 10 ++++++++++
> include/uapi/linux/kvm.h | 1 +
> 5 files changed, 29 insertions(+), 3 deletions(-)
>
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -181,7 +181,8 @@ struct kvm_s390_sie_block {
> __u16 ipa; /* 0x0056 */
> __u32 ipb; /* 0x0058 */
> __u32 scaoh; /* 0x005c */
> - __u8 reserved60; /* 0x0060 */
> +#define FPF_BPBC 0x20
> + __u8 fpf; /* 0x0060 */
> __u8 ecb; /* 0x0061 */
> __u8 ecb2; /* 0x0062 */
> #define ECB3_AES 0x04
> --- a/arch/s390/include/uapi/asm/kvm.h
> +++ b/arch/s390/include/uapi/asm/kvm.h
> @@ -197,6 +197,7 @@ struct kvm_guest_debug_arch {
> #define KVM_SYNC_VRS (1UL << 6)
> #define KVM_SYNC_RICCB (1UL << 7)
> #define KVM_SYNC_FPRS (1UL << 8)
> +#define KVM_SYNC_BPBC (1UL << 10)
> /* definition of registers in kvm_run */
> struct kvm_sync_regs {
> __u64 prefix; /* prefix register */
> @@ -217,7 +218,9 @@ struct kvm_sync_regs {
> };
> __u8 reserved[512]; /* for future vector expansion */
> __u32 fpc; /* valid on KVM_SYNC_VRS or KVM_SYNC_FPRS */
> - __u8 padding[52]; /* riccb needs to be 64byte aligned */
> + __u8 bpbc : 1; /* bp mode */
> + __u8 reserved2 : 7;
> + __u8 padding1[51]; /* riccb needs to be 64byte aligned */
> __u8 riccb[64]; /* runtime instrumentation controls block */
> };
>
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -401,6 +401,9 @@ int kvm_vm_ioctl_check_extension(struct
> case KVM_CAP_S390_RI:
> r = test_facility(64);
> break;
> + case KVM_CAP_S390_BPB:
> + r = test_facility(82);
> + break;
> default:
> r = 0;
> }
> @@ -1713,6 +1716,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *
> kvm_s390_set_prefix(vcpu, 0);
> if (test_kvm_facility(vcpu->kvm, 64))
> vcpu->run->kvm_valid_regs |= KVM_SYNC_RICCB;
> + if (test_kvm_facility(vcpu->kvm, 82))
> + vcpu->run->kvm_valid_regs |= KVM_SYNC_BPBC;
> /* fprs can be synchronized via vrs, even if the guest has no vx. With
> * MACHINE_HAS_VX, (load|store)_fpu_regs() will work with vrs format.
> */
> @@ -1829,7 +1834,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu
> if (test_fp_ctl(current->thread.fpu.fpc))
> /* User space provided an invalid FPC, let's clear it */
> current->thread.fpu.fpc = 0;
> -
> save_access_regs(vcpu->arch.host_acrs);
> restore_access_regs(vcpu->run->s.regs.acrs);
> gmap_enable(vcpu->arch.enabled_gmap);
> @@ -1877,6 +1881,7 @@ static void kvm_s390_vcpu_initial_reset(
> current->thread.fpu.fpc = 0;
> vcpu->arch.sie_block->gbea = 1;
> vcpu->arch.sie_block->pp = 0;
> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC;
> vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
> kvm_clear_async_pf_completion_queue(vcpu);
> if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
> @@ -2744,6 +2749,11 @@ static void sync_regs(struct kvm_vcpu *v
> if (riccb->valid)
> vcpu->arch.sie_block->ecb3 |= 0x01;
> }
> + if ((kvm_run->kvm_dirty_regs & KVM_SYNC_BPBC) &&
> + test_kvm_facility(vcpu->kvm, 82)) {
> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC;
> + vcpu->arch.sie_block->fpf |= kvm_run->s.regs.bpbc ? FPF_BPBC : 0;
> + }
>
> kvm_run->kvm_dirty_regs = 0;
> }
> @@ -2762,6 +2772,7 @@ static void store_regs(struct kvm_vcpu *
> kvm_run->s.regs.pft = vcpu->arch.pfault_token;
> kvm_run->s.regs.pfs = vcpu->arch.pfault_select;
> kvm_run->s.regs.pfc = vcpu->arch.pfault_compare;
> + kvm_run->s.regs.bpbc = (vcpu->arch.sie_block->fpf & FPF_BPBC) == FPF_BPBC;
> }
>
> int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
> --- a/arch/s390/kvm/vsie.c
> +++ b/arch/s390/kvm/vsie.c
> @@ -217,6 +217,12 @@ static void unshadow_scb(struct kvm_vcpu
> memcpy(scb_o->gcr, scb_s->gcr, 128);
> scb_o->pp = scb_s->pp;
>
> + /* branch prediction */
> + if (test_kvm_facility(vcpu->kvm, 82)) {
> + scb_o->fpf &= ~FPF_BPBC;
> + scb_o->fpf |= scb_s->fpf & FPF_BPBC;
> + }
> +
> /* interrupt intercept */
> switch (scb_s->icptcode) {
> case ICPT_PROGI:
> @@ -259,6 +265,7 @@ static int shadow_scb(struct kvm_vcpu *v
> scb_s->ecb3 = 0;
> scb_s->ecd = 0;
> scb_s->fac = 0;
> + scb_s->fpf = 0;
>
> rc = prepare_cpuflags(vcpu, vsie_page);
> if (rc)
> @@ -316,6 +323,9 @@ static int shadow_scb(struct kvm_vcpu *v
> prefix_unmapped(vsie_page);
> scb_s->ecb |= scb_o->ecb & 0x10U;
> }
> + /* branch prediction */
> + if (test_kvm_facility(vcpu->kvm, 82))
> + scb_s->fpf |= scb_o->fpf & FPF_BPBC;
> /* SIMD */
> if (test_kvm_facility(vcpu->kvm, 129)) {
> scb_s->eca |= scb_o->eca & 0x00020000U;
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -870,6 +870,7 @@ struct kvm_ppc_smmu_info {
> #define KVM_CAP_S390_USER_INSTR0 130
> #define KVM_CAP_MSI_DEVID 131
> #define KVM_CAP_PPC_HTM 132
> +#define KVM_CAP_S390_BPB 152
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
>
>