* [PATCH v4 0/2] s390: virtio: let arch validate VIRTIO features @ 2020-07-07 8:44 Pierre Morel 2020-07-07 8:44 ` [PATCH v4 1/2] " Pierre Morel 2020-07-07 8:44 ` [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection Pierre Morel 0 siblings, 2 replies; 14+ messages in thread From: Pierre Morel @ 2020-07-07 8:44 UTC (permalink / raw) To: linux-kernel Cc: pasic, borntraeger, frankja, mst, jasowang, cohuck, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor Hi all, I changed the patch subject to reflect the content, becoming more general. 1) I removed the ack from Christian and Jason even far as I understand they gave it for the functionality more than for the implementation. @Jason, @Christian, please can I get back your acked-by with these changes? 2) previous patch had another name: [PATCH v3 0/1] s390: virtio: let arch choose to accept devices without IOMMU feature id: Message-Id: <1592390637-17441-2-git-send-email-pmorel@linux.ibm.com> 3) The new version generalize the validation of the features by the architecture, making it not IOMMU_PLATFORM specific anymore inside virtio.c The architecture specific code for s390 is now testing the virtio features. 4) Since I reworked the patch I also moved the arch specific code from arch/s390/mm/init.c to arch/s390/kernel/to uv.c 5) Finaly, I splitted the patch into generic virtio and arch specific code. Regards, Pierre Pierre Morel (2): virtio: let arch validate VIRTIO features s390: virtio: PV needs VIRTIO I/O device protection arch/s390/kernel/uv.c | 25 +++++++++++++++++++++++++ drivers/virtio/virtio.c | 19 +++++++++++++++++++ include/linux/virtio_config.h | 1 + 3 files changed, 45 insertions(+) -- 2.25.1 Changelog to v4: - separate virtio and arch code (Pierre) - moved code from arch/s390/mm/init.c to arch/s390/kernel/uv.c (Heiko) - moved validation inside the arch code (Connie) - moved the call to arch validation before VIRTIO_F_1 test (Michael) to v3: - add warning (Connie, Christian) - add comment (Connie) - change hook name (Halil, Connie) to v2: - put the test in virtio_finalize_features() (Connie) - put the test inside VIRTIO core (Jason) - pass a virtio device as parameter (Halil) ^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v4 1/2] virtio: let arch validate VIRTIO features 2020-07-07 8:44 [PATCH v4 0/2] s390: virtio: let arch validate VIRTIO features Pierre Morel @ 2020-07-07 8:44 ` Pierre Morel 2020-07-07 9:26 ` Cornelia Huck 2020-07-07 8:44 ` [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection Pierre Morel 1 sibling, 1 reply; 14+ messages in thread From: Pierre Morel @ 2020-07-07 8:44 UTC (permalink / raw) To: linux-kernel Cc: pasic, borntraeger, frankja, mst, jasowang, cohuck, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor An architecture may need to validate the VIRTIO devices features based on architecture specificities. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> --- drivers/virtio/virtio.c | 19 +++++++++++++++++++ include/linux/virtio_config.h | 1 + 2 files changed, 20 insertions(+) diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index a977e32a88f2..3179a8aa76f5 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -167,6 +167,21 @@ void virtio_add_status(struct virtio_device *dev, unsigned int status) } EXPORT_SYMBOL_GPL(virtio_add_status); +/* + * arch_needs_virtio_iommu_platform - provide arch specific hook when finalizing + * features for VIRTIO device dev + * @dev: the VIRTIO device being added + * + * Permits the platform to provide architecture specific functionality when + * devices features are finalized. This is the default implementation. + * Architecture implementations can override this. + */ + +int __weak arch_validate_virtio_features(struct virtio_device *dev) +{ + return 0; +} + int virtio_finalize_features(struct virtio_device *dev) { int ret = dev->config->finalize_features(dev); @@ -176,6 +191,10 @@ int virtio_finalize_features(struct virtio_device *dev) if (ret) return ret; + ret = arch_validate_virtio_features(dev); + if (ret) + return ret; + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) return 0; diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index bb4cc4910750..3f4117adf311 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -459,4 +459,5 @@ static inline void virtio_cwrite64(struct virtio_device *vdev, _r; \ }) +int arch_validate_virtio_features(struct virtio_device *dev); #endif /* _LINUX_VIRTIO_CONFIG_H */ -- 2.25.1 ^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH v4 1/2] virtio: let arch validate VIRTIO features 2020-07-07 8:44 ` [PATCH v4 1/2] " Pierre Morel @ 2020-07-07 9:26 ` Cornelia Huck 2020-07-07 10:39 ` Pierre Morel 2020-07-07 11:09 ` Christian Borntraeger 0 siblings, 2 replies; 14+ messages in thread From: Cornelia Huck @ 2020-07-07 9:26 UTC (permalink / raw) To: Pierre Morel Cc: linux-kernel, pasic, borntraeger, frankja, mst, jasowang, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On Tue, 7 Jul 2020 10:44:36 +0200 Pierre Morel <pmorel@linux.ibm.com> wrote: > An architecture may need to validate the VIRTIO devices features > based on architecture specificities. s/specifities/specifics/ > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > --- > drivers/virtio/virtio.c | 19 +++++++++++++++++++ > include/linux/virtio_config.h | 1 + > 2 files changed, 20 insertions(+) > > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c > index a977e32a88f2..3179a8aa76f5 100644 > --- a/drivers/virtio/virtio.c > +++ b/drivers/virtio/virtio.c > @@ -167,6 +167,21 @@ void virtio_add_status(struct virtio_device *dev, unsigned int status) > } > EXPORT_SYMBOL_GPL(virtio_add_status); > > +/* > + * arch_needs_virtio_iommu_platform - provide arch specific hook when finalizing s/arch_needs_virtio_iommu_platform/arch_validate_virtio_features/ :) > + * features for VIRTIO device dev > + * @dev: the VIRTIO device being added > + * > + * Permits the platform to provide architecture specific functionality when s/provide architecture specific functionality/handle architecture-specific requirements/ ? > + * devices features are finalized. This is the default implementation. s/devices/device/ > + * Architecture implementations can override this. > + */ > + > +int __weak arch_validate_virtio_features(struct virtio_device *dev) > +{ > + return 0; > +} > + > int virtio_finalize_features(struct virtio_device *dev) > { > int ret = dev->config->finalize_features(dev); > @@ -176,6 +191,10 @@ int virtio_finalize_features(struct virtio_device *dev) > if (ret) > return ret; > > + ret = arch_validate_virtio_features(dev); > + if (ret) > + return ret; > + > if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) > return 0; > > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h > index bb4cc4910750..3f4117adf311 100644 > --- a/include/linux/virtio_config.h > +++ b/include/linux/virtio_config.h > @@ -459,4 +459,5 @@ static inline void virtio_cwrite64(struct virtio_device *vdev, > _r; \ > }) > > +int arch_validate_virtio_features(struct virtio_device *dev); > #endif /* _LINUX_VIRTIO_CONFIG_H */ With the wording fixed, Reviewed-by: Cornelia Huck <cohuck@redhat.com> ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4 1/2] virtio: let arch validate VIRTIO features 2020-07-07 9:26 ` Cornelia Huck @ 2020-07-07 10:39 ` Pierre Morel 2020-07-07 11:09 ` Christian Borntraeger 1 sibling, 0 replies; 14+ messages in thread From: Pierre Morel @ 2020-07-07 10:39 UTC (permalink / raw) To: Cornelia Huck Cc: linux-kernel, pasic, borntraeger, frankja, mst, jasowang, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On 2020-07-07 11:26, Cornelia Huck wrote: > On Tue, 7 Jul 2020 10:44:36 +0200 > Pierre Morel <pmorel@linux.ibm.com> wrote: > >> An architecture may need to validate the VIRTIO devices features >> based on architecture specificities. > > s/specifities/specifics/ OK > >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >> --- >> drivers/virtio/virtio.c | 19 +++++++++++++++++++ >> include/linux/virtio_config.h | 1 + >> 2 files changed, 20 insertions(+) >> >> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c >> index a977e32a88f2..3179a8aa76f5 100644 >> --- a/drivers/virtio/virtio.c >> +++ b/drivers/virtio/virtio.c >> @@ -167,6 +167,21 @@ void virtio_add_status(struct virtio_device *dev, unsigned int status) >> } >> EXPORT_SYMBOL_GPL(virtio_add_status); >> >> +/* >> + * arch_needs_virtio_iommu_platform - provide arch specific hook when finalizing > > s/arch_needs_virtio_iommu_platform/arch_validate_virtio_features/ > > :) grrr... yes. > >> + * features for VIRTIO device dev >> + * @dev: the VIRTIO device being added >> + * >> + * Permits the platform to provide architecture specific functionality when > > s/provide architecture specific functionality/handle architecture-specific requirements/ > > ? better, thanks. > >> + * devices features are finalized. This is the default implementation. > > s/devices/device/ yes. > >> + * Architecture implementations can override this. >> + */ >> + >> +int __weak arch_validate_virtio_features(struct virtio_device *dev) >> +{ >> + return 0; >> +} >> + >> int virtio_finalize_features(struct virtio_device *dev) >> { >> int ret = dev->config->finalize_features(dev); >> @@ -176,6 +191,10 @@ int virtio_finalize_features(struct virtio_device *dev) >> if (ret) >> return ret; >> >> + ret = arch_validate_virtio_features(dev); >> + if (ret) >> + return ret; >> + >> if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) >> return 0; >> >> diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h >> index bb4cc4910750..3f4117adf311 100644 >> --- a/include/linux/virtio_config.h >> +++ b/include/linux/virtio_config.h >> @@ -459,4 +459,5 @@ static inline void virtio_cwrite64(struct virtio_device *vdev, >> _r; \ >> }) >> >> +int arch_validate_virtio_features(struct virtio_device *dev); >> #endif /* _LINUX_VIRTIO_CONFIG_H */ > > With the wording fixed, > > Reviewed-by: Cornelia Huck <cohuck@redhat.com> > Thanks for the review. regards, Pierre -- Pierre Morel IBM Lab Boeblingen ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4 1/2] virtio: let arch validate VIRTIO features 2020-07-07 9:26 ` Cornelia Huck 2020-07-07 10:39 ` Pierre Morel @ 2020-07-07 11:09 ` Christian Borntraeger 2020-07-07 11:17 ` Pierre Morel 1 sibling, 1 reply; 14+ messages in thread From: Christian Borntraeger @ 2020-07-07 11:09 UTC (permalink / raw) To: Cornelia Huck, Pierre Morel Cc: linux-kernel, pasic, frankja, mst, jasowang, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On 07.07.20 11:26, Cornelia Huck wrote: > On Tue, 7 Jul 2020 10:44:36 +0200 > Pierre Morel <pmorel@linux.ibm.com> wrote: > >> An architecture may need to validate the VIRTIO devices features >> based on architecture specificities. > > s/specifities/specifics/ > >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >> --- >> drivers/virtio/virtio.c | 19 +++++++++++++++++++ >> include/linux/virtio_config.h | 1 + >> 2 files changed, 20 insertions(+) >> >> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c >> index a977e32a88f2..3179a8aa76f5 100644 >> --- a/drivers/virtio/virtio.c >> +++ b/drivers/virtio/virtio.c >> @@ -167,6 +167,21 @@ void virtio_add_status(struct virtio_device *dev, unsigned int status) >> } >> EXPORT_SYMBOL_GPL(virtio_add_status); >> >> +/* >> + * arch_needs_virtio_iommu_platform - provide arch specific hook when finalizing > > s/arch_needs_virtio_iommu_platform/arch_validate_virtio_features/ With the things from Conny fixed, Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4 1/2] virtio: let arch validate VIRTIO features 2020-07-07 11:09 ` Christian Borntraeger @ 2020-07-07 11:17 ` Pierre Morel 0 siblings, 0 replies; 14+ messages in thread From: Pierre Morel @ 2020-07-07 11:17 UTC (permalink / raw) To: Christian Borntraeger, Cornelia Huck Cc: linux-kernel, pasic, frankja, mst, jasowang, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On 2020-07-07 13:09, Christian Borntraeger wrote: > > > On 07.07.20 11:26, Cornelia Huck wrote: >> On Tue, 7 Jul 2020 10:44:36 +0200 >> Pierre Morel <pmorel@linux.ibm.com> wrote: >> >>> An architecture may need to validate the VIRTIO devices features >>> based on architecture specificities. >> >> s/specifities/specifics/ yes >> >>> >>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >>> --- >>> drivers/virtio/virtio.c | 19 +++++++++++++++++++ >>> include/linux/virtio_config.h | 1 + >>> 2 files changed, 20 insertions(+) >>> >>> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c >>> index a977e32a88f2..3179a8aa76f5 100644 >>> --- a/drivers/virtio/virtio.c >>> +++ b/drivers/virtio/virtio.c >>> @@ -167,6 +167,21 @@ void virtio_add_status(struct virtio_device *dev, unsigned int status) >>> } >>> EXPORT_SYMBOL_GPL(virtio_add_status); >>> >>> +/* >>> + * arch_needs_virtio_iommu_platform - provide arch specific hook when finalizing >> >> s/arch_needs_virtio_iommu_platform/arch_validate_virtio_features/ > > With the things from Conny fixed, > > Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> > Thanks, Pierre -- Pierre Morel IBM Lab Boeblingen ^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection 2020-07-07 8:44 [PATCH v4 0/2] s390: virtio: let arch validate VIRTIO features Pierre Morel 2020-07-07 8:44 ` [PATCH v4 1/2] " Pierre Morel @ 2020-07-07 8:44 ` Pierre Morel 2020-07-07 9:46 ` Cornelia Huck 2020-07-07 11:12 ` Christian Borntraeger 1 sibling, 2 replies; 14+ messages in thread From: Pierre Morel @ 2020-07-07 8:44 UTC (permalink / raw) To: linux-kernel Cc: pasic, borntraeger, frankja, mst, jasowang, cohuck, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor S390, protecting the guest memory against unauthorized host access needs to enforce VIRTIO I/O device protection through the use of VIRTIO_F_VERSION_1 and VIRTIO_F_IOMMU_PLATFORM. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> --- arch/s390/kernel/uv.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index c296e5c8dbf9..106330f6eda1 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -14,6 +14,7 @@ #include <linux/memblock.h> #include <linux/pagemap.h> #include <linux/swap.h> +#include <linux/virtio_config.h> #include <asm/facility.h> #include <asm/sections.h> #include <asm/uv.h> @@ -413,3 +414,27 @@ static int __init uv_info_init(void) } device_initcall(uv_info_init); #endif + +/* + * arch_validate_virtio_iommu_platform + * @dev: the VIRTIO device being added + * + * Return value: returns -ENODEV if any features of the + * device breaks the protected virtualization + * 0 otherwise. + */ +int arch_validate_virtio_features(struct virtio_device *dev) +{ + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { + dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n"); + return is_prot_virt_guest() ? -ENODEV : 0; + } + + if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { + dev_warn(&dev->dev, + "device must provide VIRTIO_F_IOMMU_PLATFORM\n"); + return is_prot_virt_guest() ? -ENODEV : 0; + } + + return 0; +} -- 2.25.1 ^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection 2020-07-07 8:44 ` [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection Pierre Morel @ 2020-07-07 9:46 ` Cornelia Huck 2020-07-07 10:38 ` Pierre Morel 2020-07-07 11:14 ` Michael S. Tsirkin 2020-07-07 11:12 ` Christian Borntraeger 1 sibling, 2 replies; 14+ messages in thread From: Cornelia Huck @ 2020-07-07 9:46 UTC (permalink / raw) To: Pierre Morel Cc: linux-kernel, pasic, borntraeger, frankja, mst, jasowang, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On Tue, 7 Jul 2020 10:44:37 +0200 Pierre Morel <pmorel@linux.ibm.com> wrote: > S390, protecting the guest memory against unauthorized host access > needs to enforce VIRTIO I/O device protection through the use of > VIRTIO_F_VERSION_1 and VIRTIO_F_IOMMU_PLATFORM. Hm... what about: "If protected virtualization is active on s390, the virtio queues are not accessible to the host, unless VIRTIO_F_IOMMU_PLATFORM has been negotiated. Use the new arch_validate_virtio_features() interface to enforce this." > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > --- > arch/s390/kernel/uv.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c > index c296e5c8dbf9..106330f6eda1 100644 > --- a/arch/s390/kernel/uv.c > +++ b/arch/s390/kernel/uv.c > @@ -14,6 +14,7 @@ > #include <linux/memblock.h> > #include <linux/pagemap.h> > #include <linux/swap.h> > +#include <linux/virtio_config.h> > #include <asm/facility.h> > #include <asm/sections.h> > #include <asm/uv.h> > @@ -413,3 +414,27 @@ static int __init uv_info_init(void) > } > device_initcall(uv_info_init); > #endif > + > +/* > + * arch_validate_virtio_iommu_platform s/arch_validate_virtio_iommu_platform/arch_validate_virtio_features/ > + * @dev: the VIRTIO device being added > + * > + * Return value: returns -ENODEV if any features of the > + * device breaks the protected virtualization > + * 0 otherwise. I don't think you need to specify the contract here: that belongs to the definition in the virtio core. What about simply adding a sentence "Return an error if required features are missing on a guest running with protected virtualization." ? > + */ > +int arch_validate_virtio_features(struct virtio_device *dev) > +{ Maybe jump out immediately if the guest is not protected? > + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { > + dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n"); > + return is_prot_virt_guest() ? -ENODEV : 0; > + } > + > + if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { > + dev_warn(&dev->dev, > + "device must provide VIRTIO_F_IOMMU_PLATFORM\n"); > + return is_prot_virt_guest() ? -ENODEV : 0; > + } if (!is_prot_virt_guest()) return 0; if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { dev_warn(&dev->dev, "legacy virtio is incompatible with protected guests"); return -ENODEV; } if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { dev_warn(&dev->dev, "device does not work with limited memory access in protected guests"); return -ENODEV; } > + > + return 0; > +} ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection 2020-07-07 9:46 ` Cornelia Huck @ 2020-07-07 10:38 ` Pierre Morel 2020-07-07 11:19 ` Halil Pasic 2020-07-07 11:14 ` Michael S. Tsirkin 1 sibling, 1 reply; 14+ messages in thread From: Pierre Morel @ 2020-07-07 10:38 UTC (permalink / raw) To: Cornelia Huck Cc: linux-kernel, pasic, borntraeger, frankja, mst, jasowang, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On 2020-07-07 11:46, Cornelia Huck wrote: > On Tue, 7 Jul 2020 10:44:37 +0200 > Pierre Morel <pmorel@linux.ibm.com> wrote: > >> S390, protecting the guest memory against unauthorized host access >> needs to enforce VIRTIO I/O device protection through the use of >> VIRTIO_F_VERSION_1 and VIRTIO_F_IOMMU_PLATFORM. > > Hm... what about: > > "If protected virtualization is active on s390, the virtio queues are > not accessible to the host, unless VIRTIO_F_IOMMU_PLATFORM has been > negotiated. Use the new arch_validate_virtio_features() interface to > enforce this." Yes, thanks. > >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >> --- >> arch/s390/kernel/uv.c | 25 +++++++++++++++++++++++++ >> 1 file changed, 25 insertions(+) >> >> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c >> index c296e5c8dbf9..106330f6eda1 100644 >> --- a/arch/s390/kernel/uv.c >> +++ b/arch/s390/kernel/uv.c >> @@ -14,6 +14,7 @@ >> #include <linux/memblock.h> >> #include <linux/pagemap.h> >> #include <linux/swap.h> >> +#include <linux/virtio_config.h> >> #include <asm/facility.h> >> #include <asm/sections.h> >> #include <asm/uv.h> >> @@ -413,3 +414,27 @@ static int __init uv_info_init(void) >> } >> device_initcall(uv_info_init); >> #endif >> + >> +/* >> + * arch_validate_virtio_iommu_platform > > s/arch_validate_virtio_iommu_platform/arch_validate_virtio_features/ > >> + * @dev: the VIRTIO device being added >> + * >> + * Return value: returns -ENODEV if any features of the >> + * device breaks the protected virtualization >> + * 0 otherwise. > > I don't think you need to specify the contract here: that belongs to > the definition in the virtio core. What about simply adding a sentence > "Return an error if required features are missing on a guest running > with protected virtualization." ? OK, right. > >> + */ >> +int arch_validate_virtio_features(struct virtio_device *dev) >> +{ > > Maybe jump out immediately if the guest is not protected? > >> + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { >> + dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n"); >> + return is_prot_virt_guest() ? -ENODEV : 0; >> + } >> + >> + if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { >> + dev_warn(&dev->dev, >> + "device must provide VIRTIO_F_IOMMU_PLATFORM\n"); >> + return is_prot_virt_guest() ? -ENODEV : 0; >> + } > > if (!is_prot_virt_guest()) > return 0; > > if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { > dev_warn(&dev->dev, > "legacy virtio is incompatible with protected guests"); > return -ENODEV; > } > > if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { > dev_warn(&dev->dev, > "device does not work with limited memory access in protected guests"); > return -ENODEV; > } Yes, easier to read. Thanks, Pierre -- Pierre Morel IBM Lab Boeblingen ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection 2020-07-07 10:38 ` Pierre Morel @ 2020-07-07 11:19 ` Halil Pasic 0 siblings, 0 replies; 14+ messages in thread From: Halil Pasic @ 2020-07-07 11:19 UTC (permalink / raw) To: Pierre Morel Cc: Cornelia Huck, linux-kernel, borntraeger, frankja, mst, jasowang, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On Tue, 7 Jul 2020 12:38:17 +0200 Pierre Morel <pmorel@linux.ibm.com> wrote: > > > On 2020-07-07 11:46, Cornelia Huck wrote: > > On Tue, 7 Jul 2020 10:44:37 +0200 > > Pierre Morel <pmorel@linux.ibm.com> wrote: > > > >> S390, protecting the guest memory against unauthorized host access > >> needs to enforce VIRTIO I/O device protection through the use of > >> VIRTIO_F_VERSION_1 and VIRTIO_F_IOMMU_PLATFORM. > > > > Hm... what about: > > > > "If protected virtualization is active on s390, the virtio queues are > > not accessible to the host, unless VIRTIO_F_IOMMU_PLATFORM has been > > negotiated. Use the new arch_validate_virtio_features() interface to > > enforce this." > > Yes, thanks. > > > > > >> > >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > >> --- > >> arch/s390/kernel/uv.c | 25 +++++++++++++++++++++++++ Is this the right place to put this stuff? This file seems to be about implementing the interface for interacting with the ultravisor. I would rather expect something like arch/s390/kernel/virtio.c Should we ever get arch hooks for balloon those could go in arch/s390/kernel/virtio.c as well. > >> 1 file changed, 25 insertions(+) > >> > >> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c > >> index c296e5c8dbf9..106330f6eda1 100644 > >> --- a/arch/s390/kernel/uv.c > >> +++ b/arch/s390/kernel/uv.c > >> @@ -14,6 +14,7 @@ > >> #include <linux/memblock.h> > >> #include <linux/pagemap.h> > >> #include <linux/swap.h> > >> +#include <linux/virtio_config.h> > >> #include <asm/facility.h> > >> #include <asm/sections.h> > >> #include <asm/uv.h> > >> @@ -413,3 +414,27 @@ static int __init uv_info_init(void) > >> } > >> device_initcall(uv_info_init); > >> #endif > >> + > >> +/* > >> + * arch_validate_virtio_iommu_platform > > > > s/arch_validate_virtio_iommu_platform/arch_validate_virtio_features/ > > > >> + * @dev: the VIRTIO device being added > >> + * > >> + * Return value: returns -ENODEV if any features of the > >> + * device breaks the protected virtualization > >> + * 0 otherwise. > > > > I don't think you need to specify the contract here: that belongs to > > the definition in the virtio core. What about simply adding a sentence > > "Return an error if required features are missing on a guest running > > with protected virtualization." ? > > OK, right. > > > > >> + */ > >> +int arch_validate_virtio_features(struct virtio_device *dev) > >> +{ > > > > Maybe jump out immediately if the guest is not protected? > > > >> + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { > >> + dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n"); > >> + return is_prot_virt_guest() ? -ENODEV : 0; > >> + } > >> + > >> + if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { > >> + dev_warn(&dev->dev, > >> + "device must provide VIRTIO_F_IOMMU_PLATFORM\n"); > >> + return is_prot_virt_guest() ? -ENODEV : 0; > >> + } > > > > if (!is_prot_virt_guest()) > > return 0; > > > > if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { > > dev_warn(&dev->dev, > > "legacy virtio is incompatible with protected guests"); > > return -ENODEV; > > } > > > > if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { > > dev_warn(&dev->dev, > > "device does not work with limited memory access in protected guests"); > > return -ENODEV; > > } > > Yes, easier to read. > Not only easier to read but does not produce warnings if !is_prot_virt_guest(). I strongly prefer the variant proposed by Connie. Otherwise LGTM. Regards, Halil ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection 2020-07-07 9:46 ` Cornelia Huck 2020-07-07 10:38 ` Pierre Morel @ 2020-07-07 11:14 ` Michael S. Tsirkin 2020-07-07 11:19 ` Pierre Morel 1 sibling, 1 reply; 14+ messages in thread From: Michael S. Tsirkin @ 2020-07-07 11:14 UTC (permalink / raw) To: Cornelia Huck Cc: Pierre Morel, linux-kernel, pasic, borntraeger, frankja, jasowang, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On Tue, Jul 07, 2020 at 11:46:33AM +0200, Cornelia Huck wrote: > On Tue, 7 Jul 2020 10:44:37 +0200 > Pierre Morel <pmorel@linux.ibm.com> wrote: > > > S390, protecting the guest memory against unauthorized host access > > needs to enforce VIRTIO I/O device protection through the use of > > VIRTIO_F_VERSION_1 and VIRTIO_F_IOMMU_PLATFORM. > > Hm... what about: > > "If protected virtualization is active on s390, the virtio queues are > not accessible to the host, unless VIRTIO_F_IOMMU_PLATFORM has been > negotiated. Use the new arch_validate_virtio_features() interface to > enforce this." s/enforce this/fail probe if that's not the case, preventing a host error on access attempt/ > > > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > > --- > > arch/s390/kernel/uv.c | 25 +++++++++++++++++++++++++ > > 1 file changed, 25 insertions(+) > > > > diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c > > index c296e5c8dbf9..106330f6eda1 100644 > > --- a/arch/s390/kernel/uv.c > > +++ b/arch/s390/kernel/uv.c > > @@ -14,6 +14,7 @@ > > #include <linux/memblock.h> > > #include <linux/pagemap.h> > > #include <linux/swap.h> > > +#include <linux/virtio_config.h> > > #include <asm/facility.h> > > #include <asm/sections.h> > > #include <asm/uv.h> > > @@ -413,3 +414,27 @@ static int __init uv_info_init(void) > > } > > device_initcall(uv_info_init); > > #endif > > + > > +/* > > + * arch_validate_virtio_iommu_platform > > s/arch_validate_virtio_iommu_platform/arch_validate_virtio_features/ > > > + * @dev: the VIRTIO device being added > > + * > > + * Return value: returns -ENODEV if any features of the > > + * device breaks the protected virtualization > > + * 0 otherwise. > > I don't think you need to specify the contract here: that belongs to > the definition in the virtio core. What about simply adding a sentence > "Return an error if required features are missing on a guest running > with protected virtualization." ? > > > + */ > > +int arch_validate_virtio_features(struct virtio_device *dev) > > +{ > > Maybe jump out immediately if the guest is not protected? > > > + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { > > + dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n"); > > + return is_prot_virt_guest() ? -ENODEV : 0; > > + } > > + > > + if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { > > + dev_warn(&dev->dev, > > + "device must provide VIRTIO_F_IOMMU_PLATFORM\n"); > > + return is_prot_virt_guest() ? -ENODEV : 0; > > + } > > if (!is_prot_virt_guest()) > return 0; > > if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { > dev_warn(&dev->dev, > "legacy virtio is incompatible with protected guests"); > return -ENODEV; > } > > if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { > dev_warn(&dev->dev, > "device does not work with limited memory access in protected guests"); > return -ENODEV; > } > > > + > > + return 0; > > +} ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection 2020-07-07 11:14 ` Michael S. Tsirkin @ 2020-07-07 11:19 ` Pierre Morel 0 siblings, 0 replies; 14+ messages in thread From: Pierre Morel @ 2020-07-07 11:19 UTC (permalink / raw) To: Michael S. Tsirkin, Cornelia Huck Cc: linux-kernel, pasic, borntraeger, frankja, jasowang, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On 2020-07-07 13:14, Michael S. Tsirkin wrote: > On Tue, Jul 07, 2020 at 11:46:33AM +0200, Cornelia Huck wrote: >> On Tue, 7 Jul 2020 10:44:37 +0200 >> Pierre Morel <pmorel@linux.ibm.com> wrote: >> >>> S390, protecting the guest memory against unauthorized host access >>> needs to enforce VIRTIO I/O device protection through the use of >>> VIRTIO_F_VERSION_1 and VIRTIO_F_IOMMU_PLATFORM. >> >> Hm... what about: >> >> "If protected virtualization is active on s390, the virtio queues are >> not accessible to the host, unless VIRTIO_F_IOMMU_PLATFORM has been >> negotiated. Use the new arch_validate_virtio_features() interface to >> enforce this." > > s/enforce this/fail probe if that's not the case, preventing a host error on access attempt/ > yes, more complete, thanks. regards, Pierre -- Pierre Morel IBM Lab Boeblingen ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection 2020-07-07 8:44 ` [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection Pierre Morel 2020-07-07 9:46 ` Cornelia Huck @ 2020-07-07 11:12 ` Christian Borntraeger 2020-07-07 11:16 ` Pierre Morel 1 sibling, 1 reply; 14+ messages in thread From: Christian Borntraeger @ 2020-07-07 11:12 UTC (permalink / raw) To: Pierre Morel, linux-kernel Cc: pasic, frankja, mst, jasowang, cohuck, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On 07.07.20 10:44, Pierre Morel wrote: > S390, protecting the guest memory against unauthorized host access > needs to enforce VIRTIO I/O device protection through the use of > VIRTIO_F_VERSION_1 and VIRTIO_F_IOMMU_PLATFORM. > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > --- > arch/s390/kernel/uv.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c > index c296e5c8dbf9..106330f6eda1 100644 > --- a/arch/s390/kernel/uv.c > +++ b/arch/s390/kernel/uv.c > @@ -14,6 +14,7 @@ > #include <linux/memblock.h> > #include <linux/pagemap.h> > #include <linux/swap.h> > +#include <linux/virtio_config.h> > #include <asm/facility.h> > #include <asm/sections.h> > #include <asm/uv.h> > @@ -413,3 +414,27 @@ static int __init uv_info_init(void) > } > device_initcall(uv_info_init); > #endif > + > +/* > + * arch_validate_virtio_iommu_platform > + * @dev: the VIRTIO device being added > + * > + * Return value: returns -ENODEV if any features of the > + * device breaks the protected virtualization > + * 0 otherwise. > + */ > +int arch_validate_virtio_features(struct virtio_device *dev) > +{ > + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { > + dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n"); I think you only want to warn if is_prot_virt_guest is true? We certainly want to be able to run as a guest of older hypervisors with virtio 0.95, no? > + return is_prot_virt_guest() ? -ENODEV : 0; > + } > + > + if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { > + dev_warn(&dev->dev, > + "device must provide VIRTIO_F_IOMMU_PLATFORM\n"); same here. > + return is_prot_virt_guest() ? -ENODEV : 0; > + } > + > + return 0; > +} > ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection 2020-07-07 11:12 ` Christian Borntraeger @ 2020-07-07 11:16 ` Pierre Morel 0 siblings, 0 replies; 14+ messages in thread From: Pierre Morel @ 2020-07-07 11:16 UTC (permalink / raw) To: Christian Borntraeger, linux-kernel Cc: pasic, frankja, mst, jasowang, cohuck, kvm, linux-s390, virtualization, thomas.lendacky, david, linuxram, heiko.carstens, gor On 2020-07-07 13:12, Christian Borntraeger wrote: > > > On 07.07.20 10:44, Pierre Morel wrote: >> S390, protecting the guest memory against unauthorized host access >> needs to enforce VIRTIO I/O device protection through the use of >> VIRTIO_F_VERSION_1 and VIRTIO_F_IOMMU_PLATFORM. >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >> --- >> arch/s390/kernel/uv.c | 25 +++++++++++++++++++++++++ >> 1 file changed, 25 insertions(+) >> >> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c >> index c296e5c8dbf9..106330f6eda1 100644 >> --- a/arch/s390/kernel/uv.c >> +++ b/arch/s390/kernel/uv.c >> @@ -14,6 +14,7 @@ >> #include <linux/memblock.h> >> #include <linux/pagemap.h> >> #include <linux/swap.h> >> +#include <linux/virtio_config.h> >> #include <asm/facility.h> >> #include <asm/sections.h> >> #include <asm/uv.h> >> @@ -413,3 +414,27 @@ static int __init uv_info_init(void) >> } >> device_initcall(uv_info_init); >> #endif >> + >> +/* >> + * arch_validate_virtio_iommu_platform >> + * @dev: the VIRTIO device being added >> + * >> + * Return value: returns -ENODEV if any features of the >> + * device breaks the protected virtualization >> + * 0 otherwise. >> + */ >> +int arch_validate_virtio_features(struct virtio_device *dev) >> +{ >> + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { >> + dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n"); > > I think you only want to warn if is_prot_virt_guest is true? We certainly > want to be able to run as a guest of older hypervisors with virtio 0.95, no? clear, yes. I will first check for PV as Connie sugested. > > >> + return is_prot_virt_guest() ? -ENODEV : 0; >> + } >> + >> + if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { >> + dev_warn(&dev->dev, >> + "device must provide VIRTIO_F_IOMMU_PLATFORM\n"); > > same here. Yes, Thanks, Pierre -- Pierre Morel IBM Lab Boeblingen ^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2020-07-07 11:19 UTC | newest] Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-07-07 8:44 [PATCH v4 0/2] s390: virtio: let arch validate VIRTIO features Pierre Morel 2020-07-07 8:44 ` [PATCH v4 1/2] " Pierre Morel 2020-07-07 9:26 ` Cornelia Huck 2020-07-07 10:39 ` Pierre Morel 2020-07-07 11:09 ` Christian Borntraeger 2020-07-07 11:17 ` Pierre Morel 2020-07-07 8:44 ` [PATCH v4 2/2] s390: virtio: PV needs VIRTIO I/O device protection Pierre Morel 2020-07-07 9:46 ` Cornelia Huck 2020-07-07 10:38 ` Pierre Morel 2020-07-07 11:19 ` Halil Pasic 2020-07-07 11:14 ` Michael S. Tsirkin 2020-07-07 11:19 ` Pierre Morel 2020-07-07 11:12 ` Christian Borntraeger 2020-07-07 11:16 ` Pierre Morel
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).