Re: [PATCH V6 0/6] Fast mmio eventfd fixes
On Mon, Nov 09, 2015 at 12:35:45PM +0800, Jason Wang wrote: > > > On 11/09/2015 01:11 AM, Michael S. Tsirkin wrote: > > On Tue, Sep 15, 2015 at 02:41:53PM +0800, Jason Wang wrote: > >> Hi: > >> > >> This series fixes two issues of fast mmio eventfd: > >> > >> 1) A single iodev instance were registerd on two buses: KVM_MMIO_BUS > >>and KVM_FAST_MMIO_BUS. This will cause double in > >>ioeventfd_destructor() > >> 2) A zero length iodev on KVM_MMIO_BUS will never be found but > >>kvm_io_bus_cmp(). This will lead e.g the eventfd will be trapped by > >>qemu instead of host. > >> > >> 1 is fixed by allocating two instances of iodev and introduce a new > >> capability for userspace. 2 is fixed by ignore the actual length if > >> the length of iodev is zero in kvm_io_bus_cmp(). > >> > >> Please review. > >> Changes from V5: > >> - move patch of explicitly checking for KVM_MMIO_BUS to patch 1 and > >> remove the unnecessary checks > >> - even more grammar and typo fixes > >> - rabase to kvm.git > >> - document KVM_CAP_FAST_MMIO > > What's up with userspace using this capability? > > It was renamed to KVM_CAP_IOEVENTFD_ANY_LENGTH. > > > Did patches ever get posted? > > See https://lkml.org/lkml/2015/9/28/208 Talking about userspace here. QEMU freeze is approaching, it really should use this to avoid regressions. > > > >> Changes from V4: > >> - move the location of kvm_assign_ioeventfd() in patch 1 which reduce > >> the change set. > >> - commit log typo fixes > >> - switch to use kvm_deassign_ioeventfd_id) when fail to register to > >> fast mmio bus > >> - change kvm_io_bus_cmp() as Paolo's suggestions > >> - introduce a new capability to avoid new userspace crash old kernel > >> - add a new patch that only try to register mmio eventfd on fast mmio > >> bus > >> > >> Changes from V3: > >> > >> - Don't do search on two buses when trying to do write on > >> KVM_MMIO_BUS. This fixes a small regression found by vmexit.flat. > >> - Since we don't do search on two buses, change kvm_io_bus_cmp() to > >> let it can find zero length iodevs. > >> - Fix the unnecessary lines in tracepoint patch. > >> > >> Changes from V2: > >> - Tweak styles and comment suggested by Cornelia. > >> > >> Changes from v1: > >> - change ioeventfd_bus_from_flags() to return KVM_FAST_MMIO_BUS when > >> needed to save lots of unnecessary changes. > >> > >> Jason Wang (6): > >> kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd > >> kvm: factor out core eventfd assign/deassign logic > >> kvm: fix double free for fast mmio eventfd > >> kvm: fix zero length mmio searching > >> kvm: add tracepoint for fast mmio > >> kvm: add fast mmio capabilitiy > >> > >> Documentation/virtual/kvm/api.txt | 7 ++- > >> arch/x86/kvm/trace.h | 18 ++ > >> arch/x86/kvm/vmx.c| 1 + > >> arch/x86/kvm/x86.c| 1 + > >> include/uapi/linux/kvm.h | 1 + > >> virt/kvm/eventfd.c| 124 > >> ++ > >> virt/kvm/kvm_main.c | 20 +- > >> 7 files changed, 118 insertions(+), 54 deletions(-) > >> > >> -- > >> 2.1.4 > > -- > > To unsubscribe from this list: send the line "unsubscribe kvm" in > > the body of a message to majord...@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH V6 0/6] Fast mmio eventfd fixes
On 11/10/2015 04:19 AM, Michael S. Tsirkin wrote: > On Mon, Nov 09, 2015 at 12:35:45PM +0800, Jason Wang wrote: >> > >> > >> > On 11/09/2015 01:11 AM, Michael S. Tsirkin wrote: >>> > > On Tue, Sep 15, 2015 at 02:41:53PM +0800, Jason Wang wrote: > >> Hi: > >> > >> This series fixes two issues of fast mmio eventfd: > >> > >> 1) A single iodev instance were registerd on two buses: KVM_MMIO_BUS > >>and KVM_FAST_MMIO_BUS. This will cause double in > >>ioeventfd_destructor() > >> 2) A zero length iodev on KVM_MMIO_BUS will never be found but > >>kvm_io_bus_cmp(). This will lead e.g the eventfd will be trapped by > >>qemu instead of host. > >> > >> 1 is fixed by allocating two instances of iodev and introduce a new > >> capability for userspace. 2 is fixed by ignore the actual length if > >> the length of iodev is zero in kvm_io_bus_cmp(). > >> > >> Please review. > >> Changes from V5: > >> - move patch of explicitly checking for KVM_MMIO_BUS to patch 1 and > >> remove the unnecessary checks > >> - even more grammar and typo fixes > >> - rabase to kvm.git > >> - document KVM_CAP_FAST_MMIO >>> > > What's up with userspace using this capability? >> > >> > It was renamed to KVM_CAP_IOEVENTFD_ANY_LENGTH. >> > >>> > > Did patches ever get posted? >> > >> > See https://lkml.org/lkml/2015/9/28/208 > Talking about userspace here. > QEMU freeze is approaching, it really should > use this to avoid regressions. > The patches were posted at http://lists.gnu.org/archive/html/qemu-devel/2015-11/msg01276.html (you were in cc list) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH V6 0/6] Fast mmio eventfd fixes
On Tue, Sep 15, 2015 at 02:41:53PM +0800, Jason Wang wrote: > Hi: > > This series fixes two issues of fast mmio eventfd: > > 1) A single iodev instance were registerd on two buses: KVM_MMIO_BUS >and KVM_FAST_MMIO_BUS. This will cause double in >ioeventfd_destructor() > 2) A zero length iodev on KVM_MMIO_BUS will never be found but >kvm_io_bus_cmp(). This will lead e.g the eventfd will be trapped by >qemu instead of host. > > 1 is fixed by allocating two instances of iodev and introduce a new > capability for userspace. 2 is fixed by ignore the actual length if > the length of iodev is zero in kvm_io_bus_cmp(). > > Please review. > Changes from V5: > - move patch of explicitly checking for KVM_MMIO_BUS to patch 1 and > remove the unnecessary checks > - even more grammar and typo fixes > - rabase to kvm.git > - document KVM_CAP_FAST_MMIO What's up with userspace using this capability? Did patches ever get posted? > > Changes from V4: > - move the location of kvm_assign_ioeventfd() in patch 1 which reduce > the change set. > - commit log typo fixes > - switch to use kvm_deassign_ioeventfd_id) when fail to register to > fast mmio bus > - change kvm_io_bus_cmp() as Paolo's suggestions > - introduce a new capability to avoid new userspace crash old kernel > - add a new patch that only try to register mmio eventfd on fast mmio > bus > > Changes from V3: > > - Don't do search on two buses when trying to do write on > KVM_MMIO_BUS. This fixes a small regression found by vmexit.flat. > - Since we don't do search on two buses, change kvm_io_bus_cmp() to > let it can find zero length iodevs. > - Fix the unnecessary lines in tracepoint patch. > > Changes from V2: > - Tweak styles and comment suggested by Cornelia. > > Changes from v1: > - change ioeventfd_bus_from_flags() to return KVM_FAST_MMIO_BUS when > needed to save lots of unnecessary changes. > > Jason Wang (6): > kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd > kvm: factor out core eventfd assign/deassign logic > kvm: fix double free for fast mmio eventfd > kvm: fix zero length mmio searching > kvm: add tracepoint for fast mmio > kvm: add fast mmio capabilitiy > > Documentation/virtual/kvm/api.txt | 7 ++- > arch/x86/kvm/trace.h | 18 ++ > arch/x86/kvm/vmx.c| 1 + > arch/x86/kvm/x86.c| 1 + > include/uapi/linux/kvm.h | 1 + > virt/kvm/eventfd.c| 124 > ++ > virt/kvm/kvm_main.c | 20 +- > 7 files changed, 118 insertions(+), 54 deletions(-) > > -- > 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH V6 0/6] Fast mmio eventfd fixes
On 11/09/2015 01:11 AM, Michael S. Tsirkin wrote: > On Tue, Sep 15, 2015 at 02:41:53PM +0800, Jason Wang wrote: >> Hi: >> >> This series fixes two issues of fast mmio eventfd: >> >> 1) A single iodev instance were registerd on two buses: KVM_MMIO_BUS >>and KVM_FAST_MMIO_BUS. This will cause double in >>ioeventfd_destructor() >> 2) A zero length iodev on KVM_MMIO_BUS will never be found but >>kvm_io_bus_cmp(). This will lead e.g the eventfd will be trapped by >>qemu instead of host. >> >> 1 is fixed by allocating two instances of iodev and introduce a new >> capability for userspace. 2 is fixed by ignore the actual length if >> the length of iodev is zero in kvm_io_bus_cmp(). >> >> Please review. >> Changes from V5: >> - move patch of explicitly checking for KVM_MMIO_BUS to patch 1 and >> remove the unnecessary checks >> - even more grammar and typo fixes >> - rabase to kvm.git >> - document KVM_CAP_FAST_MMIO > What's up with userspace using this capability? It was renamed to KVM_CAP_IOEVENTFD_ANY_LENGTH. > Did patches ever get posted? See https://lkml.org/lkml/2015/9/28/208 > >> Changes from V4: >> - move the location of kvm_assign_ioeventfd() in patch 1 which reduce >> the change set. >> - commit log typo fixes >> - switch to use kvm_deassign_ioeventfd_id) when fail to register to >> fast mmio bus >> - change kvm_io_bus_cmp() as Paolo's suggestions >> - introduce a new capability to avoid new userspace crash old kernel >> - add a new patch that only try to register mmio eventfd on fast mmio >> bus >> >> Changes from V3: >> >> - Don't do search on two buses when trying to do write on >> KVM_MMIO_BUS. This fixes a small regression found by vmexit.flat. >> - Since we don't do search on two buses, change kvm_io_bus_cmp() to >> let it can find zero length iodevs. >> - Fix the unnecessary lines in tracepoint patch. >> >> Changes from V2: >> - Tweak styles and comment suggested by Cornelia. >> >> Changes from v1: >> - change ioeventfd_bus_from_flags() to return KVM_FAST_MMIO_BUS when >> needed to save lots of unnecessary changes. >> >> Jason Wang (6): >> kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd >> kvm: factor out core eventfd assign/deassign logic >> kvm: fix double free for fast mmio eventfd >> kvm: fix zero length mmio searching >> kvm: add tracepoint for fast mmio >> kvm: add fast mmio capabilitiy >> >> Documentation/virtual/kvm/api.txt | 7 ++- >> arch/x86/kvm/trace.h | 18 ++ >> arch/x86/kvm/vmx.c| 1 + >> arch/x86/kvm/x86.c| 1 + >> include/uapi/linux/kvm.h | 1 + >> virt/kvm/eventfd.c| 124 >> ++ >> virt/kvm/kvm_main.c | 20 +- >> 7 files changed, 118 insertions(+), 54 deletions(-) >> >> -- >> 2.1.4 > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH V6 0/6] Fast mmio eventfd fixes
On 15/09/2015 21:26, Michael S. Tsirkin wrote: > > Applied to kvm/queue and will send patches 1-4 for 4.3-rc. Thanks! > > I'd prefer at least 6 to be there as well: > without 6 userspace can't safely use the code, and without 5, > it can't trace it. The idea is to just make old userspace work without crashing. New features do not belong in stable releases. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH V6 0/6] Fast mmio eventfd fixes
Hi: This series fixes two issues of fast mmio eventfd: 1) A single iodev instance were registerd on two buses: KVM_MMIO_BUS and KVM_FAST_MMIO_BUS. This will cause double in ioeventfd_destructor() 2) A zero length iodev on KVM_MMIO_BUS will never be found but kvm_io_bus_cmp(). This will lead e.g the eventfd will be trapped by qemu instead of host. 1 is fixed by allocating two instances of iodev and introduce a new capability for userspace. 2 is fixed by ignore the actual length if the length of iodev is zero in kvm_io_bus_cmp(). Please review. Changes from V5: - move patch of explicitly checking for KVM_MMIO_BUS to patch 1 and remove the unnecessary checks - even more grammar and typo fixes - rabase to kvm.git - document KVM_CAP_FAST_MMIO Changes from V4: - move the location of kvm_assign_ioeventfd() in patch 1 which reduce the change set. - commit log typo fixes - switch to use kvm_deassign_ioeventfd_id) when fail to register to fast mmio bus - change kvm_io_bus_cmp() as Paolo's suggestions - introduce a new capability to avoid new userspace crash old kernel - add a new patch that only try to register mmio eventfd on fast mmio bus Changes from V3: - Don't do search on two buses when trying to do write on KVM_MMIO_BUS. This fixes a small regression found by vmexit.flat. - Since we don't do search on two buses, change kvm_io_bus_cmp() to let it can find zero length iodevs. - Fix the unnecessary lines in tracepoint patch. Changes from V2: - Tweak styles and comment suggested by Cornelia. Changes from v1: - change ioeventfd_bus_from_flags() to return KVM_FAST_MMIO_BUS when needed to save lots of unnecessary changes. Jason Wang (6): kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd kvm: factor out core eventfd assign/deassign logic kvm: fix double free for fast mmio eventfd kvm: fix zero length mmio searching kvm: add tracepoint for fast mmio kvm: add fast mmio capabilitiy Documentation/virtual/kvm/api.txt | 7 ++- arch/x86/kvm/trace.h | 18 ++ arch/x86/kvm/vmx.c| 1 + arch/x86/kvm/x86.c| 1 + include/uapi/linux/kvm.h | 1 + virt/kvm/eventfd.c| 124 ++ virt/kvm/kvm_main.c | 20 +- 7 files changed, 118 insertions(+), 54 deletions(-) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH V6 0/6] Fast mmio eventfd fixes
On 15/09/2015 08:41, Jason Wang wrote: > Hi: > > This series fixes two issues of fast mmio eventfd: > > 1) A single iodev instance were registerd on two buses: KVM_MMIO_BUS >and KVM_FAST_MMIO_BUS. This will cause double in >ioeventfd_destructor() > 2) A zero length iodev on KVM_MMIO_BUS will never be found but >kvm_io_bus_cmp(). This will lead e.g the eventfd will be trapped by >qemu instead of host. > > 1 is fixed by allocating two instances of iodev and introduce a new > capability for userspace. 2 is fixed by ignore the actual length if > the length of iodev is zero in kvm_io_bus_cmp(). > > Please review. Applied to kvm/queue and will send patches 1-4 for 4.3-rc. Thanks! Paolo > Changes from V5: > - move patch of explicitly checking for KVM_MMIO_BUS to patch 1 and > remove the unnecessary checks > - even more grammar and typo fixes > - rabase to kvm.git > - document KVM_CAP_FAST_MMIO > > Changes from V4: > - move the location of kvm_assign_ioeventfd() in patch 1 which reduce > the change set. > - commit log typo fixes > - switch to use kvm_deassign_ioeventfd_id) when fail to register to > fast mmio bus > - change kvm_io_bus_cmp() as Paolo's suggestions > - introduce a new capability to avoid new userspace crash old kernel > - add a new patch that only try to register mmio eventfd on fast mmio > bus > > Changes from V3: > > - Don't do search on two buses when trying to do write on > KVM_MMIO_BUS. This fixes a small regression found by vmexit.flat. > - Since we don't do search on two buses, change kvm_io_bus_cmp() to > let it can find zero length iodevs. > - Fix the unnecessary lines in tracepoint patch. > > Changes from V2: > - Tweak styles and comment suggested by Cornelia. > > Changes from v1: > - change ioeventfd_bus_from_flags() to return KVM_FAST_MMIO_BUS when > needed to save lots of unnecessary changes. > > Jason Wang (6): > kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd > kvm: factor out core eventfd assign/deassign logic > kvm: fix double free for fast mmio eventfd > kvm: fix zero length mmio searching > kvm: add tracepoint for fast mmio > kvm: add fast mmio capabilitiy > > Documentation/virtual/kvm/api.txt | 7 ++- > arch/x86/kvm/trace.h | 18 ++ > arch/x86/kvm/vmx.c| 1 + > arch/x86/kvm/x86.c| 1 + > include/uapi/linux/kvm.h | 1 + > virt/kvm/eventfd.c| 124 > ++ > virt/kvm/kvm_main.c | 20 +- > 7 files changed, 118 insertions(+), 54 deletions(-) > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH V6 0/6] Fast mmio eventfd fixes
On Tue, Sep 15, 2015 at 05:08:49PM +0200, Paolo Bonzini wrote: > > > On 15/09/2015 08:41, Jason Wang wrote: > > Hi: > > > > This series fixes two issues of fast mmio eventfd: > > > > 1) A single iodev instance were registerd on two buses: KVM_MMIO_BUS > >and KVM_FAST_MMIO_BUS. This will cause double in > >ioeventfd_destructor() > > 2) A zero length iodev on KVM_MMIO_BUS will never be found but > >kvm_io_bus_cmp(). This will lead e.g the eventfd will be trapped by > >qemu instead of host. > > > > 1 is fixed by allocating two instances of iodev and introduce a new > > capability for userspace. 2 is fixed by ignore the actual length if > > the length of iodev is zero in kvm_io_bus_cmp(). > > > > Please review. > > Applied to kvm/queue and will send patches 1-4 for 4.3-rc. Thanks! > > Paolo I'd prefer at least 6 to be there as well: without 6 userspace can't safely use the code, and without 5, it can't trace it. > > Changes from V5: > > - move patch of explicitly checking for KVM_MMIO_BUS to patch 1 and > > remove the unnecessary checks > > - even more grammar and typo fixes > > - rabase to kvm.git > > - document KVM_CAP_FAST_MMIO > > > > Changes from V4: > > - move the location of kvm_assign_ioeventfd() in patch 1 which reduce > > the change set. > > - commit log typo fixes > > - switch to use kvm_deassign_ioeventfd_id) when fail to register to > > fast mmio bus > > - change kvm_io_bus_cmp() as Paolo's suggestions > > - introduce a new capability to avoid new userspace crash old kernel > > - add a new patch that only try to register mmio eventfd on fast mmio > > bus > > > > Changes from V3: > > > > - Don't do search on two buses when trying to do write on > > KVM_MMIO_BUS. This fixes a small regression found by vmexit.flat. > > - Since we don't do search on two buses, change kvm_io_bus_cmp() to > > let it can find zero length iodevs. > > - Fix the unnecessary lines in tracepoint patch. > > > > Changes from V2: > > - Tweak styles and comment suggested by Cornelia. > > > > Changes from v1: > > - change ioeventfd_bus_from_flags() to return KVM_FAST_MMIO_BUS when > > needed to save lots of unnecessary changes. > > > > Jason Wang (6): > > kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd > > kvm: factor out core eventfd assign/deassign logic > > kvm: fix double free for fast mmio eventfd > > kvm: fix zero length mmio searching > > kvm: add tracepoint for fast mmio > > kvm: add fast mmio capabilitiy > > > > Documentation/virtual/kvm/api.txt | 7 ++- > > arch/x86/kvm/trace.h | 18 ++ > > arch/x86/kvm/vmx.c| 1 + > > arch/x86/kvm/x86.c| 1 + > > include/uapi/linux/kvm.h | 1 + > > virt/kvm/eventfd.c| 124 > > ++ > > virt/kvm/kvm_main.c | 20 +- > > 7 files changed, 118 insertions(+), 54 deletions(-) > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
