From: Christian Borntraeger <borntraeger@xxxxxxxxxx>
[ 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>
---
arch/s390/include/asm/kvm_host.h | 3 ++-
arch/s390/include/uapi/asm/kvm.h | 3 +++
arch/s390/kvm/kvm-s390.c | 13 ++++++++++++-
include/uapi/linux/kvm.h | 1 +
4 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index e9a983f40a24..7d9c5917da2b 100644
--- 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 ef1a5fcc6c66..3aec52253c04 100644
--- 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 23e3f5d77a24..3166516639d6 100644
--- 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;
}
@@ -1262,6 +1265,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
KVM_SYNC_CRS |
KVM_SYNC_ARCH0 |
KVM_SYNC_PFAULT;
+ if (test_kvm_facility(vcpu->kvm, 82))
+ vcpu->run->kvm_valid_regs |= KVM_SYNC_BPBC;
if (test_kvm_facility(vcpu->kvm, 129))
vcpu->run->kvm_valid_regs |= KVM_SYNC_VRS;
@@ -1286,7 +1291,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
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.gmap);
@@ -1327,6 +1331,7 @@ 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))
@@ -2162,6 +2167,7 @@ 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)
@@ -2194,6 +2200,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
kvm_run->exit_reason = KVM_EXIT_INTR;
rc = -EINTR;
}
+ 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;
+ }
if (guestdbg_exit_pending(vcpu) && !rc) {
kvm_s390_prepare_debug_exit(vcpu);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 03f3618612aa..376d0ab5b9f2 100644
--- 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
--
2.13.5