From: Alexander Graf <agraf@suse.de>
To: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH 02/23] KVM: PPC: Book3S PR: Don't corrupt guest state when kernel uses VMX
Date: Thu, 29 Aug 2013 00:51:42 +0200 [thread overview]
Message-ID: <05464227-9242-4B0A-834B-BD71EA70150F@suse.de> (raw)
In-Reply-To: <20130806041433.GH19254@iris.ozlabs.ibm.com>
On 06.08.2013, at 06:14, Paul Mackerras wrote:
> Currently the code assumes that once we load up guest FP/VSX or VMX
> state into the CPU, it stays valid in the CPU registers until we
> explicitly flush it to the thread_struct. However, on POWER7,
> copy_page() and memcpy() can use VMX. These functions do flush the
> VMX state to the thread_struct before using VMX instructions, but if
> this happens while we have guest state in the VMX registers, and we
> then re-enter the guest, we don't reload the VMX state from the
> thread_struct, leading to guest corruption. This has been observed
> to cause guest processes to segfault.
>
> To fix this, we check before re-entering the guest that all of the
> bits corresponding to facilities owned by the guest, as expressed
> in vcpu->arch.guest_owned_ext, are set in current->thread.regs->msr.
> Any bits that have been cleared correspond to facilities that have
> been used by kernel code and thus flushed to the thread_struct, so
> for them we reload the state from the thread_struct.
>
> We also need to check current->thread.regs->msr before calling
> giveup_fpu() or giveup_altivec(), since if the relevant bit is
> clear, the state has already been flushed to the thread_struct and
> to flush it again would corrupt it.
>
> Signed-off-by: Paul Mackerras <paulus@samba.org>
Thanks, applied to kvm-ppc-queue.
Alex
WARNING: multiple messages have this Message-ID (diff)
From: Alexander Graf <agraf@suse.de>
To: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH 02/23] KVM: PPC: Book3S PR: Don't corrupt guest state when kernel uses VMX
Date: Wed, 28 Aug 2013 22:51:42 +0000 [thread overview]
Message-ID: <05464227-9242-4B0A-834B-BD71EA70150F@suse.de> (raw)
In-Reply-To: <20130806041433.GH19254@iris.ozlabs.ibm.com>
On 06.08.2013, at 06:14, Paul Mackerras wrote:
> Currently the code assumes that once we load up guest FP/VSX or VMX
> state into the CPU, it stays valid in the CPU registers until we
> explicitly flush it to the thread_struct. However, on POWER7,
> copy_page() and memcpy() can use VMX. These functions do flush the
> VMX state to the thread_struct before using VMX instructions, but if
> this happens while we have guest state in the VMX registers, and we
> then re-enter the guest, we don't reload the VMX state from the
> thread_struct, leading to guest corruption. This has been observed
> to cause guest processes to segfault.
>
> To fix this, we check before re-entering the guest that all of the
> bits corresponding to facilities owned by the guest, as expressed
> in vcpu->arch.guest_owned_ext, are set in current->thread.regs->msr.
> Any bits that have been cleared correspond to facilities that have
> been used by kernel code and thus flushed to the thread_struct, so
> for them we reload the state from the thread_struct.
>
> We also need to check current->thread.regs->msr before calling
> giveup_fpu() or giveup_altivec(), since if the relevant bit is
> clear, the state has already been flushed to the thread_struct and
> to flush it again would corrupt it.
>
> Signed-off-by: Paul Mackerras <paulus@samba.org>
Thanks, applied to kvm-ppc-queue.
Alex
next prev parent reply other threads:[~2013-08-28 22:51 UTC|newest]
Thread overview: 136+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-06 4:12 [PATCH 00/23] Allow PR and HV KVM to coexist in one kernel Paul Mackerras
2013-08-06 4:12 ` Paul Mackerras
2013-08-06 4:13 ` [PATCH 01/23] KVM: PPC: Book3S: Fix compile error in XICS emulation Paul Mackerras
2013-08-06 4:13 ` Paul Mackerras
2013-08-28 22:51 ` Alexander Graf
2013-08-28 22:51 ` Alexander Graf
2013-08-06 4:14 ` [PATCH 02/23] KVM: PPC: Book3S PR: Don't corrupt guest state when kernel uses VMX Paul Mackerras
2013-08-06 4:14 ` Paul Mackerras
2013-08-08 15:49 ` Aneesh Kumar K.V
2013-08-08 15:49 ` Aneesh Kumar K.V
2013-08-28 22:51 ` Alexander Graf [this message]
2013-08-28 22:51 ` Alexander Graf
2013-08-06 4:15 ` [PATCH 03/23] KVM: PPC: Book3S PR: Make instruction fetch fallback work for system calls Paul Mackerras
2013-08-06 4:15 ` Paul Mackerras
2013-08-28 22:51 ` Alexander Graf
2013-08-28 22:51 ` Alexander Graf
2013-08-06 4:16 ` [PATCH 04/23] KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Paul Mackerras
2013-08-06 4:16 ` Paul Mackerras
2013-08-11 11:06 ` Aneesh Kumar K.V
2013-08-11 11:18 ` Aneesh Kumar K.V
2013-08-28 22:00 ` Alexander Graf
2013-08-28 22:00 ` Alexander Graf
2013-08-29 5:04 ` Paul Mackerras
2013-08-29 5:04 ` Paul Mackerras
2013-08-29 12:46 ` Alexander Graf
2013-08-29 12:46 ` Alexander Graf
2013-08-06 4:18 ` [PATCH 05/23] KVM: PPC: Book3S PR: Rework kvmppc_mmu_book3s_64_xlate() Paul Mackerras
2013-08-06 4:18 ` Paul Mackerras
2013-08-28 22:51 ` Alexander Graf
2013-08-28 22:51 ` Alexander Graf
2013-08-06 4:18 ` [PATCH 06/23] KVM: PPC: Book3S PR: Allow guest to use 64k pages Paul Mackerras
2013-08-06 4:18 ` Paul Mackerras
2013-08-28 22:56 ` Alexander Graf
2013-08-28 22:56 ` Alexander Graf
2013-08-29 5:17 ` Paul Mackerras
2013-08-29 5:17 ` Paul Mackerras
2013-08-29 12:48 ` Alexander Graf
2013-08-29 12:48 ` Alexander Graf
2013-08-06 4:19 ` [PATCH 07/23] KVM: PPC: Book3S PR: Use 64k host pages where possible Paul Mackerras
2013-08-06 4:19 ` Paul Mackerras
2013-08-28 23:24 ` Alexander Graf
2013-08-28 23:24 ` Alexander Graf
2013-08-29 5:23 ` Paul Mackerras
2013-08-29 5:23 ` Paul Mackerras
2013-08-29 12:43 ` Alexander Graf
2013-08-29 12:43 ` Alexander Graf
2013-08-06 4:20 ` [PATCH 08/23] KVM: PPC: Book3S PR: Handle PP0 page-protection bit in guest HPTEs Paul Mackerras
2013-08-06 4:20 ` Paul Mackerras
2013-08-06 4:20 ` [PATCH 09/23] KVM: PPC: Book3S PR: Correct errors in H_ENTER implementation Paul Mackerras
2013-08-06 4:20 ` Paul Mackerras
2013-08-06 4:21 ` [PATCH 10/23] KVM: PPC: Book3S PR: Make HPT accesses and updates SMP-safe Paul Mackerras
2013-08-06 4:21 ` Paul Mackerras
2013-08-06 4:21 ` [PATCH 11/23] KVM: PPC: Book3S PR: Allocate kvm_vcpu structs from kvm_vcpu_cache Paul Mackerras
2013-08-06 4:21 ` Paul Mackerras
2013-08-12 10:03 ` Aneesh Kumar K.V
2013-08-12 10:15 ` Aneesh Kumar K.V
2013-08-06 4:22 ` [PATCH 12/23] KVM: PPC: Book3S HV: Better handling of exceptions that happen in real mode Paul Mackerras
2013-08-06 4:22 ` Paul Mackerras
2013-08-06 4:22 ` [PATCH 13/23] KVM: PPC: Book3S: Move skip-interrupt handlers to common code Paul Mackerras
2013-08-06 4:22 ` Paul Mackerras
2013-08-06 4:23 ` [PATCH 14/23] KVM: PPC: Book3S PR: Delay disabling relocation-on interrupts Paul Mackerras
2013-08-06 4:23 ` Paul Mackerras
2013-08-30 16:30 ` Alexander Graf
2013-08-30 16:30 ` Alexander Graf
2013-08-30 22:55 ` Paul Mackerras
2013-08-30 22:55 ` Paul Mackerras
2013-08-30 23:13 ` Alexander Graf
2013-08-30 23:13 ` Alexander Graf
2013-08-31 5:42 ` Paul Mackerras
2013-08-31 5:42 ` Paul Mackerras
2013-08-06 4:24 ` [PATCH 15/23] KVM: PPC: Book3S: Rename symbols that exist in both PR and HV KVM Paul Mackerras
2013-08-06 4:24 ` Paul Mackerras
2013-08-06 4:24 ` [PATCH 16/23] KVM: PPC: Book3S: Merge implementations of KVM_PPC_GET_SMMU_INFO ioctl Paul Mackerras
2013-08-06 4:24 ` Paul Mackerras
2013-08-06 4:25 ` [PATCH 17/23] KVM: PPC: Book3S HV: Factorize kvmppc_core_vcpu_create_hv() Paul Mackerras
2013-08-06 4:25 ` Paul Mackerras
2013-08-06 4:25 ` [PATCH 18/23] KVM: PPC: Book3S: Allow both PR and HV KVM to be selected Paul Mackerras
2013-08-06 4:25 ` Paul Mackerras
2013-08-06 4:26 ` [PATCH 19/23] KVM: PPC: Book3S: Select PR vs HV separately for each guest Paul Mackerras
2013-08-06 4:26 ` Paul Mackerras
2013-09-12 22:56 ` Alexander Graf
2013-09-12 22:56 ` Alexander Graf
2013-09-13 0:17 ` Paul Mackerras
2013-09-13 0:17 ` Paul Mackerras
2013-09-13 1:31 ` Benjamin Herrenschmidt
2013-09-13 1:31 ` Benjamin Herrenschmidt
2013-09-13 4:18 ` Alexander Graf
2013-09-13 4:18 ` Alexander Graf
2013-09-14 18:33 ` Aneesh Kumar K.V
2013-09-14 18:45 ` Aneesh Kumar K.V
2013-09-14 20:22 ` Alexander Graf
2013-09-14 20:22 ` Alexander Graf
2013-09-15 9:16 ` Aneesh Kumar K.V
2013-09-15 9:28 ` Aneesh Kumar K.V
2013-09-15 11:55 ` Alexander Graf
2013-09-15 11:55 ` Alexander Graf
2013-09-13 4:17 ` Alexander Graf
2013-09-13 4:17 ` Alexander Graf
2013-09-18 12:05 ` Paul Mackerras
2013-09-18 12:05 ` Paul Mackerras
2013-09-19 7:31 ` Alexander Graf
2013-09-19 7:31 ` Alexander Graf
2013-08-06 4:27 ` [PATCH 20/23] KVM: PPC: Book3S PR: Better handling of host-side read-only pages Paul Mackerras
2013-08-06 4:27 ` Paul Mackerras
2013-09-12 23:01 ` Alexander Graf
2013-09-12 23:01 ` Alexander Graf
2013-09-13 0:23 ` Paul Mackerras
2013-09-13 0:23 ` Paul Mackerras
2013-09-14 5:24 ` Paul Mackerras
2013-09-14 5:24 ` Paul Mackerras
2013-09-14 20:23 ` Alexander Graf
2013-09-14 20:23 ` Alexander Graf
2013-09-16 4:12 ` Paul Mackerras
2013-09-16 4:12 ` Paul Mackerras
2013-09-16 12:47 ` Alexander Graf
2013-09-16 12:47 ` Alexander Graf
2013-08-06 4:27 ` [PATCH 21/23] KVM: PPC: Book3S PR: Use mmu_notifier_retry() in kvmppc_mmu_map_page() Paul Mackerras
2013-08-06 4:27 ` Paul Mackerras
2013-08-07 4:13 ` Bhushan Bharat-R65777
2013-08-07 4:13 ` Bhushan Bharat-R65777
2013-08-07 4:28 ` Paul Mackerras
2013-08-07 4:28 ` Paul Mackerras
2013-08-07 5:18 ` Bhushan Bharat-R65777
2013-08-07 5:18 ` Bhushan Bharat-R65777
2013-08-07 5:17 ` Bhushan Bharat-R65777
2013-08-07 5:17 ` Bhushan Bharat-R65777
2013-08-07 8:27 ` Paul Mackerras
2013-08-07 8:27 ` Paul Mackerras
2013-08-07 8:31 ` Bhushan Bharat-R65777
2013-08-07 8:31 ` Bhushan Bharat-R65777
2013-08-08 12:06 ` Paul Mackerras
2013-08-08 12:06 ` Paul Mackerras
2013-08-06 4:27 ` [PATCH 22/23] KVM: PPC: Book3S PR: Mark pages accessed, and dirty if being written Paul Mackerras
2013-08-06 4:27 ` Paul Mackerras
2013-08-06 4:28 ` [PATCH 23/23] KVM: PPC: Book3S PR: Reduce number of shadow PTEs invalidated by MMU notifiers Paul Mackerras
2013-08-06 4:28 ` Paul Mackerras
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