From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: ACJfBovwFnaQFl2vmPyLsuFsFJY9RhU0fJfWxAWf8+OUGO8zmiPTrGO8H3xYYaijhchtFDrVokIY ARC-Seal: i=1; a=rsa-sha256; t=1516225414; cv=none; d=google.com; s=arc-20160816; b=XgnLy7bHJIYC+KYaOZQLbh4W1F+kQhQtFAc5Ww87ZmFyHXRhTwVAu61mASmQQzqo9E CEsZsnVIbwjP3PTeqameUPk55FESkRi/YLxFplYJQ0sq8qpbGg3Y0Iyf29u0NLH/I8jo PEaVW9vu8lfh0ZC54BOapvcqSyoD90DCYgJyGoMBRDQ+N2uFinSEw148QHnb4MjkWIif xEnaM78A5ar6kASKd2ZvkWJ7JF+dSpU1VPEyQCXvKF6ynQxkK2PGBET0j1z5Qo3gL2oF E4XIb2igiWeZHW9UKQTibwZJXjZJ1Kn9zCeSYXxq1OHc0+HEdD7bavTdeGZrVIkYT0TV 7pcg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=message-id:content-transfer-encoding:content-language:in-reply-to :mime-version:user-agent:date:from:references:cc:to:subject :arc-authentication-results; bh=16qW08ps/nonvcSjzeEh00/jgE4hLtLrDzX+pfAXdnE=; b=SUaimDUPvNjHKD5T5K0YpQSWXJ3LR/77DA+zrGk9tHqOztsrq8uG2mDpYlGoxJNEE3 BGEKWY1xoWSdJwQvwZTzbyDdIndl5jtAaU6NNYDPcW/UvwGlh22Ljk00LOjrKrQWlINy Ww1HROt06Ocxl+5Sx3rpuHXkrkhm+YwrDD8upOCG+KaIdKd4k7QzRnpgtGyq4uGV4VgG ZDb9Jt/OzjJMlcr0G6e/5ML2pwg9cgLBDjZaeiseYu6VPZ8YOdsHPPDFUpnzrqVFIVbx al1y9hzjGqQdl7Xgk6oo3eiWmR9dVYKcSD9niKYHEBlYdHRiIc8i1+itSf23WrAbuhMM GodQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of borntraeger@de.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=borntraeger@de.ibm.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=ibm.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of borntraeger@de.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=borntraeger@de.ibm.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=ibm.com Subject: Re: [PATCH v2] KVM: s390: wire up bpb feature To: David Hildenbrand , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, Cornelia Huck , Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= Cc: Martin Schwidefsky , Heiko Carstens , Greg Kroah-Hartman , Jon Masters , Marcus Meissner , Jiri Kosina References: <1516182519-10623-6-git-send-email-schwidefsky@de.ibm.com> <20180117134434.48676-1-borntraeger@de.ibm.com> <887651e4-10fa-9bd1-0ce6-091235a9b085@redhat.com> From: Christian Borntraeger Date: Wed, 17 Jan 2018 22:43:24 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <887651e4-10fa-9bd1-0ce6-091235a9b085@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18011721-0008-0000-0000-000004C2F729 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18011721-0009-0000-0000-00001E5667C5 Message-Id: <90ae6d5a-9f86-964b-74ca-e0971a11f497@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-01-17_11:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1801170294 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1589847455312286984?= X-GMAIL-MSGID: =?utf-8?q?1589877580852807094?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 01/17/2018 02:51 PM, David Hildenbrand wrote: > On 17.01.2018 14:44, Christian Borntraeger wrote: >> 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 >> --- >> v1->v2: - review feedback from David >> - rename seb(c) into bpb(c) >> arch/s390/include/asm/kvm_host.h | 3 ++- >> arch/s390/include/uapi/asm/kvm.h | 5 ++++- >> arch/s390/kvm/kvm-s390.c | 12 ++++++++++++ >> arch/s390/kvm/vsie.c | 10 ++++++++++ >> include/uapi/linux/kvm.h | 1 + >> 5 files changed, 29 insertions(+), 2 deletions(-) >> >> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >> index e14f381..c1b0a9a 100644 >> --- a/arch/s390/include/asm/kvm_host.h >> +++ b/arch/s390/include/asm/kvm_host.h >> @@ -207,7 +207,8 @@ struct kvm_s390_sie_block { >> __u16 ipa; /* 0x0056 */ >> __u32 ipb; /* 0x0058 */ >> __u32 scaoh; /* 0x005c */ >> - __u8 reserved60; /* 0x0060 */ >> +#define FPF_BPBC 0x20 >> + __u8 fpf; /* 0x0060 */ >> #define ECB_GS 0x40 >> #define ECB_TE 0x10 >> #define ECB_SRSI 0x04 >> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h >> index 38535a57..4cdaa55 100644 >> --- a/arch/s390/include/uapi/asm/kvm.h >> +++ b/arch/s390/include/uapi/asm/kvm.h >> @@ -224,6 +224,7 @@ struct kvm_guest_debug_arch { >> #define KVM_SYNC_RICCB (1UL << 7) >> #define KVM_SYNC_FPRS (1UL << 8) >> #define KVM_SYNC_GSCB (1UL << 9) >> +#define KVM_SYNC_BPBC (1UL << 10) >> /* length and alignment of the sdnx as a power of two */ >> #define SDNXC 8 >> #define SDNXL (1UL << SDNXC) >> @@ -247,7 +248,9 @@ struct kvm_sync_regs { >> }; >> __u8 reserved[512]; /* for future vector expansion */ >> __u32 fpc; /* valid on KVM_SYNC_VRS or KVM_SYNC_FPRS */ >> - __u8 padding1[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 */ >> __u8 padding2[192]; /* sdnx needs to be 256byte aligned */ >> union { >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index 2c93cbb..2598cf243 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -421,6 +421,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) >> case KVM_CAP_S390_GS: >> r = test_facility(133); >> break; >> + case KVM_CAP_S390_BPB: >> + r = test_facility(82); >> + break; >> default: >> r = 0; >> } >> @@ -2198,6 +2201,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *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; >> if (test_kvm_facility(vcpu->kvm, 133)) >> vcpu->run->kvm_valid_regs |= KVM_SYNC_GSCB; >> /* fprs can be synchronized via vrs, even if the guest has no vx. With >> @@ -2339,6 +2344,7 @@ 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)) >> @@ -3298,6 +3304,11 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) >> vcpu->arch.sie_block->ecd |= ECD_HOSTREGMGMT; >> vcpu->arch.gs_enabled = 1; >> } >> + 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; >> + } >> save_access_regs(vcpu->arch.host_acrs); >> restore_access_regs(vcpu->run->s.regs.acrs); >> /* save host (userspace) fprs/vrs */ >> @@ -3344,6 +3355,7 @@ 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; >> save_access_regs(vcpu->run->s.regs.acrs); >> restore_access_regs(vcpu->arch.host_acrs); >> /* Save guest register state */ >> diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c >> index 5d6ae03..7513483 100644 >> --- a/arch/s390/kvm/vsie.c >> +++ b/arch/s390/kvm/vsie.c >> @@ -223,6 +223,12 @@ static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >> 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: >> @@ -265,6 +271,7 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >> scb_s->ecb3 = 0; >> scb_s->ecd = 0; >> scb_s->fac = 0; >> + scb_s->fpf = 0; >> >> rc = prepare_cpuflags(vcpu, vsie_page); >> if (rc) >> @@ -324,6 +331,9 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >> prefix_unmapped(vsie_page); >> scb_s->ecb |= scb_o->ecb & ECB_TE; >> } >> + /* 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 & ECA_VX; >> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h >> index 496e59a..79f6050 100644 >> --- a/include/uapi/linux/kvm.h >> +++ b/include/uapi/linux/kvm.h >> @@ -932,6 +932,7 @@ struct kvm_ppc_resize_hpt { >> #define KVM_CAP_HYPERV_SYNIC2 148 >> #define KVM_CAP_HYPERV_VP_INDEX 149 >> #define KVM_CAP_S390_AIS_MIGRATION 150 >> +#define KVM_CAP_S390_BPB 151 >> >> #ifdef KVM_CAP_IRQ_ROUTING >> >> > > Reviewed-by: David Hildenbrand Thanks. Conny can you review and ack as well? Paolo, Radim, As the other patches need to sync on the ifetch/nospec/gmb naming I have changed my mind. :-) This patch is independent from the other patches (as it just provides the guest facilities not caring about what the host does). It seems that you do a kvm pull request for 4.15 anyway (for power), so it might make sense to apply this patch as well for 4.15. this will make it easier to also upstream the QEMU part in time as we need the uabi interfaces. Christian