KVM: s390: wire up bpb feature

[ 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>

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index e9a983f40a24d30b2d598ce4bcd932006efbf81f..7d9c5917da2b88244bdd92b33fd152bd6c82b7a0 100644 (file)
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -136,7 +136,8 @@ 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

diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index ef1a5fcc6c66bbf5705173b41371378c4b541483..beb508a9e72cd224284549df6444315a5bfb5283 100644 (file)
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -151,6 +151,7 @@ struct kvm_guest_debug_arch {
 #define KVM_SYNC_ARCH0  (1UL << 4)
 #define KVM_SYNC_PFAULT (1UL << 5)
 #define KVM_SYNC_VRS    (1UL << 6)
+#define KVM_SYNC_BPBC   (1UL << 10)
 /* definition of registers in kvm_run */
 struct kvm_sync_regs {
        __u64 prefix;   /* prefix register */
@@ -168,6 +169,8 @@ struct kvm_sync_regs {
        __u64 vrs[32][2];       /* vector registers */
        __u8  reserved[512];    /* for future vector expansion */
        __u32 fpc;      /* only valid with vector registers */
+       __u8 bpbc : 1;          /* bp mode */
+       __u8 reserved2 : 7;
 };
 
 #define KVM_REG_S390_TODPR     (KVM_REG_S390 | KVM_REG_SIZE_U32 | 0x1)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 23e3f5d77a2410f01dd4112238020756ae0b139d..b011140e6b0646860912042f0ac3311a70b979aa 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -257,6 +257,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
        case KVM_CAP_S390_VECTOR_REGISTERS:
                r = MACHINE_HAS_VX;
                break;
+       case KVM_CAP_S390_BPB:
+               r = test_facility(82);
+               break;
        default:
                r = 0;
        }
@@ -1264,6 +1267,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
                                    KVM_SYNC_PFAULT;
        if (test_kvm_facility(vcpu->kvm, 129))
                vcpu->run->kvm_valid_regs |= KVM_SYNC_VRS;
+       if (test_kvm_facility(vcpu->kvm, 82))
+               vcpu->run->kvm_valid_regs |= KVM_SYNC_BPBC;
 
        if (kvm_is_ucontrol(vcpu->kvm))
                return __kvm_ucontrol_vcpu_init(vcpu);
@@ -1327,6 +1332,7 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu)
        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))
@@ -2145,6 +2151,11 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
                        kvm_clear_async_pf_completion_queue(vcpu);
        }
+       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;
 }
 
@@ -2162,6 +2173,7 @@ static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
        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)

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 03f3618612aa5e1dfe97c1ad2dab0d7ee031fa31..376d0ab5b9f2b68a17f2dcbc5520982410d7a0f7 100644 (file)
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -831,6 +831,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_GUEST_DEBUG_HW_WPS 120
 #define KVM_CAP_SPLIT_IRQCHIP 121
 #define KVM_CAP_IOEVENTFD_ANY_LENGTH 122
+#define KVM_CAP_S390_BPB 152
 
 #ifdef KVM_CAP_IRQ_ROUTING