From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60298) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ykdwn-0005dE-Hu for qemu-devel@nongnu.org; Tue, 21 Apr 2015 15:35:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ykdwi-0002WE-B6 for qemu-devel@nongnu.org; Tue, 21 Apr 2015 15:35:05 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:51996) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ykdwi-0002UP-2M for qemu-devel@nongnu.org; Tue, 21 Apr 2015 15:35:00 -0400 Received: from /spool/local by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 21 Apr 2015 20:34:57 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 2A30217D8042 for ; Tue, 21 Apr 2015 20:35:34 +0100 (BST) Received: from d06av01.portsmouth.uk.ibm.com (d06av01.portsmouth.uk.ibm.com [9.149.37.212]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t3LJYtJi5767476 for ; Tue, 21 Apr 2015 19:34:55 GMT Received: from d06av01.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av01.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t3LJYs8F006374 for ; Tue, 21 Apr 2015 13:34:55 -0600 Message-ID: <5536A65E.5090204@de.ibm.com> Date: Tue, 21 Apr 2015 21:34:54 +0200 From: Christian Borntraeger MIME-Version: 1.0 References: <1428569498-27393-1-git-send-email-cornelia.huck@de.ibm.com> <1428569498-27393-10-git-send-email-cornelia.huck@de.ibm.com> <55351366.9000600@de.ibm.com> <5536A11E.5020609@suse.de> In-Reply-To: <5536A11E.5020609@suse.de> Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 09/10] s390x/mmu: Use ioctl for reading and writing from/to guest memory List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf , Cornelia Huck , qemu-devel@nongnu.org Cc: jfrei@linux.vnet.ibm.com, Thomas Huth Am 21.04.2015 um 21:12 schrieb Alexander Graf: > On 04/20/2015 04:55 PM, Christian Borntraeger wrote: >> Am 09.04.2015 um 10:51 schrieb Cornelia Huck: >>> From: Thomas Huth >>> >>> Add code to make use of the new ioctl for reading from / writing to >>> virtual guest memory. By using the ioctl, the memory accesses are now >>> protected with the so-called ipte-lock in the kernel. >>> >>> Signed-off-by: Thomas Huth >>> Signed-off-by: Cornelia Huck >> Acked-by: Christian Borntraeger >> >>> --- >>> target-s390x/cpu.h | 7 +++++++ >>> target-s390x/kvm.c | 35 +++++++++++++++++++++++++++++++++++ >>> target-s390x/mmu_helper.c | 9 +++++++++ >>> 3 files changed, 51 insertions(+) >>> >>> diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h >>> index 79bc80b..9c42743 100644 >>> --- a/target-s390x/cpu.h >>> +++ b/target-s390x/cpu.h >>> @@ -401,6 +401,8 @@ void kvm_s390_vcpu_interrupt(S390CPU *cpu, struct kvm_s390_irq *irq); >>> void kvm_s390_floating_interrupt(struct kvm_s390_irq *irq); >>> int kvm_s390_inject_flic(struct kvm_s390_irq *irq); >>> void kvm_s390_access_exception(S390CPU *cpu, uint16_t code, uint64_t te_code); >>> +int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf, int len, >>> + bool is_write); >>> int kvm_s390_get_clock(uint8_t *tod_high, uint64_t *tod_clock); >>> int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_clock); >>> #else >>> @@ -418,6 +420,11 @@ static inline int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_low) >>> { >>> return -ENOSYS; >>> } >>> +static inline int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf, >>> + int len, bool is_write) >>> +{ >>> + return -ENOSYS; >>> +} >>> static inline void kvm_s390_access_exception(S390CPU *cpu, uint16_t code, >>> uint64_t te_code) >>> { >>> diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c >>> index 619684b..e2ae2b3 100644 >>> --- a/target-s390x/kvm.c >>> +++ b/target-s390x/kvm.c >>> @@ -123,6 +123,7 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = { >>> >>> static int cap_sync_regs; >>> static int cap_async_pf; >>> +static int cap_mem_op; >>> >>> static void *legacy_s390_alloc(size_t size, uint64_t *align); >>> >>> @@ -247,6 +248,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s) >>> { >>> cap_sync_regs = kvm_check_extension(s, KVM_CAP_SYNC_REGS); >>> cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF); >>> + cap_mem_op = kvm_check_extension(s, KVM_CAP_S390_MEM_OP); >>> >>> kvm_s390_enable_cmma(s); >>> >>> @@ -550,6 +552,39 @@ int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_low) >>> return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attr); >>> } >>> >>> +/** >>> + * kvm_s390_mem_op: >>> + * @addr: the logical start address in guest memory >>> + * @hostbuf: buffer in host memory. NULL = do only checks w/o copying >>> + * @len: length that should be transfered >>> + * @is_write: true = write, false = read >>> + * Returns: 0 on success, non-zero if an exception or error occured >>> + * >>> + * Use KVM ioctl to read/write from/to guest memory. An access exception >>> + * is injected into the vCPU in case of translation errors. >>> + */ >>> +int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf, int len, >>> + bool is_write) >>> +{ >>> + struct kvm_s390_mem_op mem_op = { >>> + .gaddr = addr, >>> + .flags = KVM_S390_MEMOP_F_INJECT_EXCEPTION, >>> + .size = len, >>> + .op = is_write ? KVM_S390_MEMOP_LOGICAL_WRITE >>> + : KVM_S390_MEMOP_LOGICAL_READ, >>> + .buf = (uint64_t)hostbuf, >>> + }; >>> + >>> + if (!cap_mem_op) { >>> + return -ENOSYS; >>> + } >>> + if (!hostbuf) { >>> + mem_op.flags |= KVM_S390_MEMOP_F_CHECK_ONLY; >>> + } >>> + >>> + return kvm_vcpu_ioctl(CPU(cpu), KVM_S390_MEM_OP, &mem_op); >>> +} >>> + >>> /* >>> * Legacy layout for s390: >>> * Older S390 KVM requires the topmost vma of the RAM to be >>> diff --git a/target-s390x/mmu_helper.c b/target-s390x/mmu_helper.c >>> index 9b88498..1e7412c 100644 >>> --- a/target-s390x/mmu_helper.c >>> +++ b/target-s390x/mmu_helper.c >>> @@ -450,6 +450,15 @@ int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, void *hostbuf, >>> target_ulong *pages; >>> int ret; >>> >>> + if (kvm_enabled()) { >>> + ret = kvm_s390_mem_op(cpu, laddr, hostbuf, len, is_write); >>> + if (ret >= 0) { >>> + return ret; >>> + } else if (ret != -ENOSYS) { >>> + error_printf("kvm_s390_mem_op() failed: %s\n", strerror(-ret)); > > Won't this spill the logs like crazy when running new qemu on old kernels? kvm_s390_mem_op will return -ENOSYS if cap_mem_op is not set.