From: Xiang Zheng <zhengxiang9@huawei.com> To: Beata Michalska <beata.michalska@linaro.org> Cc: <pbonzini@redhat.com>, <mst@redhat.com>, Igor Mammedov <imammedo@redhat.com>, <shannon.zhaosl@gmail.com>, Peter Maydell <peter.maydell@linaro.org>, Laszlo Ersek <lersek@redhat.com>, <james.morse@arm.com>, gengdongjiu <gengdongjiu@huawei.com>, <mtosatti@redhat.com>, <rth@twiddle.net>, <ehabkost@redhat.com>, <jonathan.cameron@huawei.com>, <xuwei5@huawei.com>, <kvm@vger.kernel.org>, <qemu-devel@nongnu.org>, <qemu-arm@nongnu.org>, <linuxarm@huawei.com>, <wanghaibin.wang@huawei.com> Subject: Re: [RESEND PATCH v21 5/6] target-arm: kvm64: handle SIGBUS signal from kernel or KVM Date: Tue, 3 Dec 2019 11:35:07 +0800 Message-ID: <9e22a655-5333-ba65-a00d-712b5b144ff4@huawei.com> (raw) In-Reply-To: <CADSWDzsEFNMKrC6h4=r70KMzG8XX_5DS1CfGBGBCMmOTfu6qyA@mail.gmail.com> On 2019/11/27 22:17, Beata Michalska wrote: > Hi > > On Wed, 27 Nov 2019 at 12:47, Xiang Zheng <zhengxiang9@huawei.com> wrote: >> >> Hi Beata, >> >> Thanks for you review! >> > YAW > >> On 2019/11/22 23:47, Beata Michalska wrote: >>> Hi, >>> >>> On Mon, 11 Nov 2019 at 01:48, Xiang Zheng <zhengxiang9@huawei.com> wrote: >>>> >>>> From: Dongjiu Geng <gengdongjiu@huawei.com> >>>> >>>> Add a SIGBUS signal handler. In this handler, it checks the SIGBUS type, >>>> translates the host VA delivered by host to guest PA, then fills this PA >>>> to guest APEI GHES memory, then notifies guest according to the SIGBUS >>>> type. >>>> >>>> When guest accesses the poisoned memory, it will generate a Synchronous >>>> External Abort(SEA). Then host kernel gets an APEI notification and calls >>>> memory_failure() to unmapped the affected page in stage 2, finally >>>> returns to guest. >>>> >>>> Guest continues to access the PG_hwpoison page, it will trap to KVM as >>>> stage2 fault, then a SIGBUS_MCEERR_AR synchronous signal is delivered to >>>> Qemu, Qemu records this error address into guest APEI GHES memory and >>>> notifes guest using Synchronous-External-Abort(SEA). >>>> >>>> In order to inject a vSEA, we introduce the kvm_inject_arm_sea() function >>>> in which we can setup the type of exception and the syndrome information. >>>> When switching to guest, the target vcpu will jump to the synchronous >>>> external abort vector table entry. >>>> >>>> The ESR_ELx.DFSC is set to synchronous external abort(0x10), and the >>>> ESR_ELx.FnV is set to not valid(0x1), which will tell guest that FAR is >>>> not valid and hold an UNKNOWN value. These values will be set to KVM >>>> register structures through KVM_SET_ONE_REG IOCTL. >>>> >>>> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> >>>> Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com> >>>> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> >>>> --- >>>> hw/acpi/acpi_ghes.c | 297 ++++++++++++++++++++++++++++++++++++ >>>> include/hw/acpi/acpi_ghes.h | 4 + >>>> include/sysemu/kvm.h | 3 +- >>>> target/arm/cpu.h | 4 + >>>> target/arm/helper.c | 2 +- >>>> target/arm/internals.h | 5 +- >>>> target/arm/kvm64.c | 64 ++++++++ >>>> target/arm/tlb_helper.c | 2 +- >>>> target/i386/cpu.h | 2 + >>>> 9 files changed, 377 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/hw/acpi/acpi_ghes.c b/hw/acpi/acpi_ghes.c >>>> index 42c00ff3d3..f5b54990c0 100644 >>>> --- a/hw/acpi/acpi_ghes.c >>>> +++ b/hw/acpi/acpi_ghes.c >>>> @@ -39,6 +39,34 @@ >>>> /* The max size in bytes for one error block */ >>>> #define ACPI_GHES_MAX_RAW_DATA_LENGTH 0x1000 >>>> >>>> +/* >>>> + * The total size of Generic Error Data Entry >>>> + * ACPI 6.1/6.2: 18.3.2.7.1 Generic Error Data, >>>> + * Table 18-343 Generic Error Data Entry >>>> + */ >>>> +#define ACPI_GHES_DATA_LENGTH 72 >>>> + >>>> +/* >>>> + * The memory section CPER size, >>>> + * UEFI 2.6: N.2.5 Memory Error Section >>>> + */ >>>> +#define ACPI_GHES_MEM_CPER_LENGTH 80 >>>> + >>>> +/* >>>> + * Masks for block_status flags >>>> + */ >>>> +#define ACPI_GEBS_UNCORRECTABLE 1 >>> >>> Why not listing all supported statuses ? Similar to error severity below ? >>> >> >> We now only use the first bit for uncorrectable error. The correctable errors >> are handled in host and would not be delivered to QEMU. >> >> I think it's unnecessary to list all the bit masks. > > I'm not sure we are using all the error severity types either, but fair enough. >> >>>> + >>>> +/* >>>> + * Values for error_severity field >>>> + */ >>>> +enum AcpiGenericErrorSeverity { >>>> + ACPI_CPER_SEV_RECOVERABLE, >>>> + ACPI_CPER_SEV_FATAL, >>>> + ACPI_CPER_SEV_CORRECTED, >>>> + ACPI_CPER_SEV_NONE, >>>> +}; >>>> + >>>> /* >>>> * Now only support ARMv8 SEA notification type error source >>>> */ >>>> @@ -49,6 +77,16 @@ >>>> */ >>>> #define ACPI_GHES_SOURCE_GENERIC_ERROR_V2 10 >>>> >>>> +#define UUID_BE(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) \ >>>> + {{{ ((a) >> 24) & 0xff, ((a) >> 16) & 0xff, ((a) >> 8) & 0xff, (a) & 0xff, \ >>>> + ((b) >> 8) & 0xff, (b) & 0xff, \ >>>> + ((c) >> 8) & 0xff, (c) & 0xff, \ >>>> + (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) } } } >>>> + >>>> +#define UEFI_CPER_SEC_PLATFORM_MEM \ >>>> + UUID_BE(0xA5BC1114, 0x6F64, 0x4EDE, 0xB8, 0x63, 0x3E, 0x83, \ >>>> + 0xED, 0x7C, 0x83, 0xB1) >>>> + >>>> /* > > As suggested in different thread - could this be also made common with > NVMe code ? Sure, I will make it common in a separate patch. >>>> @@ -1036,6 +1062,44 @@ int kvm_arch_get_registers(CPUState *cs) >>>> return ret; >>>> } >>>> >>>> +void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr) >>>> +{ >>>> + ram_addr_t ram_addr; >>>> + hwaddr paddr; >>>> + >>>> + assert(code == BUS_MCEERR_AR || code == BUS_MCEERR_AO); >>>> + >>>> + if (acpi_enabled && addr && >>>> + object_property_get_bool(qdev_get_machine(), "ras", NULL)) { >>>> + ram_addr = qemu_ram_addr_from_host(addr); >>>> + if (ram_addr != RAM_ADDR_INVALID && >>>> + kvm_physical_memory_addr_from_host(c->kvm_state, addr, &paddr)) { >>>> + kvm_hwpoison_page_add(ram_addr); >>>> + /* >>>> + * Asynchronous signal will be masked by main thread, so >>>> + * only handle synchronous signal. >>>> + */ >>> >>> I'm not entirely sure that the comment above is correct (it has been >>> pointed out before). I would expect the AO signal to be handled here as >>> well. Not having proper support to do that just yet is another story but >>> the comment might be bit misleading. >>> >> >> We also expect the AO signal can be handled here. Maybe we could add the comment like: >> >> "Asynchronous signal is masked by main thread now. Once it can be asserted, we could >> handle it." :) >> > Still not entirely there - if I'm not mistaken. Both BUS_MCEERR_AR and > BUS_MVEERR_AO can end up here. > I'm not entirely sure what you mean by "masked by main thread" ? Both will be > handled by sigbus_handler and as such both will end up here either > directly through kvm_on_sigbus > or through kvm_cpu_exec with pending sigbus. Or am I misguided ? > In fact BUS_MCEERR_AO cannot go to here, because QEMU main thread masks the SIGBUS signal[1] and vcpu threads can only handle the BUS_MCEERR_AR. Qemu Main Thread VCPU Threads Kernel: Mask SIGBUS AO SIGBUS would be send to Qemu main thread in kernel(kill_proc()) KVM: Mask SIGBUS Only send AR SIGBUS to VCPU threads in KVM(kvm_send_hwpoison_signal()) However, maybe we shouldn't consider the behaviors of kernel or KVM and just keep the logic of handling the AO signal in kvm_arch_on_sigbus_vcpu() like what x86 version does. [1] https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg03575.html -- Thanks, Xiang
next prev parent reply index Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-11 1:40 [RESEND PATCH v21 0/6] Add ARMv8 RAS virtualization support in QEMU Xiang Zheng 2019-11-11 1:40 ` [RESEND PATCH v21 1/6] hw/arm/virt: Introduce a RAS machine option Xiang Zheng 2019-12-02 18:22 ` Peter Maydell 2019-12-07 12:10 ` gengdongjiu 2019-11-11 1:40 ` [RESEND PATCH v21 2/6] docs: APEI GHES generation and CPER record description Xiang Zheng 2019-11-15 9:44 ` Igor Mammedov 2019-11-27 1:37 ` Xiang Zheng 2019-11-27 8:12 ` Igor Mammedov 2019-11-11 1:40 ` [RESEND PATCH v21 3/6] ACPI: Add APEI GHES table generation support Xiang Zheng 2019-11-15 9:38 ` Igor Mammedov 2019-11-18 12:49 ` gengdongjiu 2019-11-18 13:18 ` gengdongjiu 2019-11-18 13:21 ` Michael S. Tsirkin 2019-11-18 13:57 ` gengdongjiu 2019-11-25 9:48 ` Igor Mammedov 2019-11-27 11:16 ` gengdongjiu 2019-11-22 15:44 ` Beata Michalska 2019-11-22 15:42 ` Beata Michalska 2019-11-25 9:23 ` Igor Mammedov 2019-11-11 1:40 ` [RESEND PATCH v21 4/6] KVM: Move hwpoison page related functions into kvm-all.c Xiang Zheng 2019-12-02 18:23 ` Peter Maydell 2019-11-11 1:40 ` [RESEND PATCH v21 5/6] target-arm: kvm64: handle SIGBUS signal from kernel or KVM Xiang Zheng 2019-11-15 16:37 ` Igor Mammedov 2019-11-22 15:47 ` Beata Michalska 2019-11-25 9:37 ` Igor Mammedov 2019-11-27 1:40 ` Xiang Zheng 2019-11-27 10:43 ` Igor Mammedov 2019-12-21 12:35 ` gengdongjiu 2019-11-22 15:47 ` Beata Michalska 2019-11-27 12:47 ` Xiang Zheng 2019-11-27 13:02 ` Igor Mammedov 2019-11-27 14:17 ` Beata Michalska 2019-12-03 3:35 ` Xiang Zheng 2019-11-27 14:17 ` Beata Michalska 2019-12-03 3:35 ` Xiang Zheng [this message] 2019-12-07 9:33 ` gengdongjiu 2019-12-09 13:05 ` Beata Michalska 2019-12-09 14:12 ` gengdongjiu 2019-11-11 1:40 ` [RESEND PATCH v21 6/6] MAINTAINERS: Add APCI/APEI/GHES entries Xiang Zheng 2019-12-02 18:27 ` [RESEND PATCH v21 0/6] Add ARMv8 RAS virtualization support in QEMU Peter Maydell 2019-12-03 2:09 ` gengdongjiu
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