Re: [PATCH 4.4 12/50] KVM: s390: wire up bpb feature
From: Greg Kroah-Hartman
Date: Mon Apr 30 2018 - 14:17:39 EST
On Sun, Apr 29, 2018 at 09:51:27AM +0200, Martin Schwidefsky wrote:
> On Fri, 27 Apr 2018 17:53:46 +0200
> Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote:
>
> > On 04/27/2018 05:46 PM, Greg Kroah-Hartman wrote:
> > > On Fri, Apr 27, 2018 at 05:17:15PM +0200, Greg Kroah-Hartman wrote:
> > >> On Fri, Apr 27, 2018 at 05:10:04PM +0200, Christian Borntraeger wrote:
> > >>>
> > >>>
> > >>> On 04/27/2018 03:58 PM, Greg Kroah-Hartman wrote:
> > >>>> 4.4-stable review patch. If anyone has any objections, please let me know.
> > >>>>
> > >>>> ------------------
> > >>>>
> > >>>> From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
> > >>>>
> > >>>>
> > >>>> From: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> > >>
> > >> Ick, that is wrong right there, my scripts messed up, this should not
> > >> have 2 author lines :(
> > >>
> > >> I'll go look at all of these, odds are it made the same error
> > >> everywhere...
> > >
> > > Yes, I've now fixed that up in the queue.
> >
> > As this patch backport was also functionally incorrect and Martin is already away
> > do you want me to send an updated version?
>
> Checked my 4.4 backport git branch and indeed the hunk is misplaced.
> Sometime I wonder about the patch tool and the hickups it can produce.
>
> My take on the replacement patch looks as follows:
>
> ---
> >From 82f20b6237a8d04378c8f4a1614bf32a6c8d8a8b Mon Sep 17 00:00:00 2001
> From: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Date: Wed, 17 Jan 2018 14:44:34 +0100
> Subject: [PATCH 03/18] KVM: s390: wire up bpb feature
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
>
> [ 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 KrÄmÃÅ <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 | 12 ++++++++++++
> include/uapi/linux/kvm.h | 1 +
> 4 files changed, 18 insertions(+), 1 deletion(-)
>
> 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..ca03c847127a 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;
>
> @@ -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 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
>
Did I include the correct version in the latest release, or do I need to
do a revert and add this one in?
thanks,
greg k-h