From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:28920 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731158AbgFWIrk (ORCPT ); Tue, 23 Jun 2020 04:47:40 -0400 Subject: Re: [PATCH v9 2/2] s390/kvm: diagnose 0x318 sync and reset From: Christian Borntraeger References: <20200622154636.5499-1-walling@linux.ibm.com> <20200622154636.5499-3-walling@linux.ibm.com> <06bd4fde-ecdb-0795-bcab-e8f5fbabcd14@redhat.com> <4387834c-7cd4-df50-294c-4f56aa14a089@de.ibm.com> Message-ID: Date: Tue, 23 Jun 2020 10:47:32 +0200 MIME-Version: 1.0 In-Reply-To: <4387834c-7cd4-df50-294c-4f56aa14a089@de.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Thomas Huth , Collin Walling , kvm@vger.kernel.org, linux-s390@vger.kernel.org Cc: pbonzini@redhat.com, frankja@linux.ibm.com, david@redhat.com, cohuck@redhat.com, imbrenda@linux.ibm.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com On 23.06.20 10:45, Christian Borntraeger wrote: > > > On 23.06.20 10:42, Thomas Huth wrote: >> On 22/06/2020 17.46, Collin Walling wrote: >>> DIAGNOSE 0x318 (diag318) sets information regarding the environment >>> the VM is running in (Linux, z/VM, etc) and is observed via >>> firmware/service events. >>> >>> This is a privileged s390x instruction that must be intercepted by >>> SIE. Userspace handles the instruction as well as migration. Data >>> is communicated via VCPU register synchronization. >>> >>> The Control Program Name Code (CPNC) is stored in the SIE block. The >>> CPNC along with the Control Program Version Code (CPVC) are stored >>> in the kvm_vcpu_arch struct. >>> >>> This data is reset on load normal and clear resets. >>> >>> Signed-off-by: Collin Walling >>> Reviewed-by: Janosch Frank >>> --- >>> arch/s390/include/asm/kvm_host.h | 4 +++- >>> arch/s390/include/uapi/asm/kvm.h | 5 ++++- >>> arch/s390/kvm/kvm-s390.c | 11 ++++++++++- >>> arch/s390/kvm/vsie.c | 1 + >>> include/uapi/linux/kvm.h | 1 + >>> 5 files changed, 19 insertions(+), 3 deletions(-) >>> >>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >>> index 3d554887794e..8bdf6f1607ca 100644 >>> --- a/arch/s390/include/asm/kvm_host.h >>> +++ b/arch/s390/include/asm/kvm_host.h >>> @@ -260,7 +260,8 @@ struct kvm_s390_sie_block { >>> __u32 scaol; /* 0x0064 */ >>> __u8 sdf; /* 0x0068 */ >>> __u8 epdx; /* 0x0069 */ >>> - __u8 reserved6a[2]; /* 0x006a */ >>> + __u8 cpnc; /* 0x006a */ >>> + __u8 reserved6b; /* 0x006b */ >>> __u32 todpr; /* 0x006c */ >>> #define GISA_FORMAT1 0x00000001 >>> __u32 gd; /* 0x0070 */ >>> @@ -745,6 +746,7 @@ struct kvm_vcpu_arch { >>> bool gs_enabled; >>> bool skey_enabled; >>> struct kvm_s390_pv_vcpu pv; >>> + union diag318_info diag318_info; >>> }; >>> >>> struct kvm_vm_stat { >>> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h >>> index 436ec7636927..2ae1b660086c 100644 >>> --- a/arch/s390/include/uapi/asm/kvm.h >>> +++ b/arch/s390/include/uapi/asm/kvm.h >>> @@ -231,11 +231,13 @@ struct kvm_guest_debug_arch { >>> #define KVM_SYNC_GSCB (1UL << 9) >>> #define KVM_SYNC_BPBC (1UL << 10) >>> #define KVM_SYNC_ETOKEN (1UL << 11) >>> +#define KVM_SYNC_DIAG318 (1UL << 12) >>> >>> #define KVM_SYNC_S390_VALID_FIELDS \ >>> (KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \ >>> KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \ >>> - KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN) >>> + KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN | \ >>> + KVM_SYNC_DIAG318) >>> >>> /* length and alignment of the sdnx as a power of two */ >>> #define SDNXC 8 >>> @@ -254,6 +256,7 @@ struct kvm_sync_regs { >>> __u64 pft; /* pfault token [PFAULT] */ >>> __u64 pfs; /* pfault select [PFAULT] */ >>> __u64 pfc; /* pfault compare [PFAULT] */ >>> + __u64 diag318; /* diagnose 0x318 info */ >>> union { >>> __u64 vrs[32][2]; /* vector registers (KVM_SYNC_VRS) */ >>> __u64 fprs[16]; /* fp registers (KVM_SYNC_FPRS) */ >> >> It's been a while since I touched kvm_sync_regs the last time ... but >> can your really extend this structure right in the middle without >> breaking older user spaces (ie. QEMUs) ? This is a uapi header ... so I >> think you rather have to add this add the end or e.g. put it into the >> padding2 region or something like that...? Or do I miss something? > > Argh. You are right. It should go to the end and not in the middle. Will fixup. > Something like this on top. diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index 2ae1b660086c..7a6b14874d65 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -256,7 +256,6 @@ struct kvm_sync_regs { __u64 pft; /* pfault token [PFAULT] */ __u64 pfs; /* pfault select [PFAULT] */ __u64 pfc; /* pfault compare [PFAULT] */ - __u64 diag318; /* diagnose 0x318 info */ union { __u64 vrs[32][2]; /* vector registers (KVM_SYNC_VRS) */ __u64 fprs[16]; /* fp registers (KVM_SYNC_FPRS) */ @@ -267,7 +266,8 @@ struct kvm_sync_regs { __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 */ + __u64 diag318; /* diagnose 0x318 info */ + __u8 padding2[184]; /* sdnx needs to be 256byte aligned */ union { __u8 sdnx[SDNXL]; /* state description annex */ struct {