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.

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From: Martin Schwidefsky schwidefsky@de.ibm.com

From: Christian Borntraeger borntraeger@de.ibm.com

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@de.ibm.com Reviewed-by: David Hildenbrand david@redhat.com Reviewed-by: Cornelia Huck cohuck@redhat.com [Changed capability number to 152. - Radim] Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Martin Schwidefsky schwidefsky@de.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

---

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