| Message ID | 1650646263-22047-6-git-send-email-olekstysh@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtio: Solution to restrict memory access under Xen using xen-grant DMA-mapping layer | expand |
On Fri, 22 Apr 2022, Oleksandr Tyshchenko wrote: > From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > > Use the presence of recently introduced "xen,dev-domid" property > in the device node as a clear indicator of enabling Xen grant > mappings scheme for that device and read the ID of Xen domain where > the corresponding backend resides. The ID (domid) is used as > an argument to the Xen grant mapping APIs. > > Also introduce xen_is_grant_dma_device() to check whether xen-grant > DMA ops need to be set for a passed device. > > Remove the hardcoded domid 0 in xen_grant_setup_dma_ops(). > > Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > --- > Changes RFC -> V1: > - new patch, split required changes from commit: > "[PATCH 4/6] virtio: Various updates to xen-virtio DMA ops layer" > - update checks in xen_virtio_setup_dma_ops() to only support > DT devices for now > - remove the "virtio,mmio" check from xen_is_virtio_device() > - remane everything according to the new naming scheme: > s/virtio/grant_dma > --- > drivers/xen/grant-dma-ops.c | 25 ++++++++++++++++++------- > include/xen/xen-ops.h | 5 +++++ > 2 files changed, 23 insertions(+), 7 deletions(-) > > diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c > index 0e69aa8..70d5d77 100644 > --- a/drivers/xen/grant-dma-ops.c > +++ b/drivers/xen/grant-dma-ops.c > @@ -66,11 +66,6 @@ static struct xen_grant_dma_data *find_xen_grant_dma_data(struct device *dev) > * Such a DMA address is formed by using the grant reference as a frame > * number and setting the highest address bit (this bit is for the backend > * to be able to distinguish it from e.g. a mmio address). > - * > - * Note that for now we hard wire dom0 to be the backend domain. In order > - * to support any domain as backend we'd need to add a way to communicate > - * the domid of this backend, e.g. via Xenstore, via the PCI-device's > - * config space or DT/ACPI. > */ > static void *xen_grant_dma_alloc(struct device *dev, size_t size, > dma_addr_t *dma_handle, gfp_t gfp, > @@ -277,6 +272,16 @@ static const struct dma_map_ops xen_grant_dma_ops = { > .dma_supported = xen_grant_dma_supported, > }; > > +bool xen_is_grant_dma_device(struct device *dev) > +{ > + /* XXX Handle only DT devices for now */ > + if (!dev->of_node) > + return false; > + > + return of_property_read_bool(dev->of_node, "xen,dev-domid"); > +} > +EXPORT_SYMBOL_GPL(xen_is_grant_dma_device); > + > void xen_grant_setup_dma_ops(struct device *dev) > { > struct xen_grant_dma_data *data; > @@ -288,8 +293,14 @@ void xen_grant_setup_dma_ops(struct device *dev) > return; > } > > - /* XXX The dom0 is hardcoded as the backend domain for now */ > - dev_domid = 0; > + /* XXX ACPI and PCI devices unsupported for now */ > + if (dev_is_pci(dev) || !dev->of_node) > + goto err; I think we can remove the "dev_is_pci" check, right? > + if (of_property_read_u32(dev->of_node, "xen,dev-domid", &dev_domid)) { > + dev_err(dev, "xen,dev-domid property is not present\n"); > + goto err; > + } > > data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); > if (!data) { > diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h > index 4f9fad5..62be9dc 100644 > --- a/include/xen/xen-ops.h > +++ b/include/xen/xen-ops.h > @@ -223,10 +223,15 @@ static inline void xen_preemptible_hcall_end(void) { } > > #ifdef CONFIG_XEN_GRANT_DMA_OPS > void xen_grant_setup_dma_ops(struct device *dev); > +bool xen_is_grant_dma_device(struct device *dev); > #else > static inline void xen_grant_setup_dma_ops(struct device *dev) > { > } > +static inline bool xen_is_grant_dma_device(struct device *dev) > +{ > + return false; > +} > #endif /* CONFIG_XEN_GRANT_DMA_OPS */ > > #endif /* INCLUDE_XEN_OPS_H */ > -- > 2.7.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
On 23.04.22 02:00, Stefano Stabellini wrote: Hello Stefano > On Fri, 22 Apr 2022, Oleksandr Tyshchenko wrote: >> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> >> >> Use the presence of recently introduced "xen,dev-domid" property >> in the device node as a clear indicator of enabling Xen grant >> mappings scheme for that device and read the ID of Xen domain where >> the corresponding backend resides. The ID (domid) is used as >> an argument to the Xen grant mapping APIs. >> >> Also introduce xen_is_grant_dma_device() to check whether xen-grant >> DMA ops need to be set for a passed device. >> >> Remove the hardcoded domid 0 in xen_grant_setup_dma_ops(). >> >> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> >> --- >> Changes RFC -> V1: >> - new patch, split required changes from commit: >> "[PATCH 4/6] virtio: Various updates to xen-virtio DMA ops layer" >> - update checks in xen_virtio_setup_dma_ops() to only support >> DT devices for now >> - remove the "virtio,mmio" check from xen_is_virtio_device() >> - remane everything according to the new naming scheme: >> s/virtio/grant_dma >> --- >> drivers/xen/grant-dma-ops.c | 25 ++++++++++++++++++------- >> include/xen/xen-ops.h | 5 +++++ >> 2 files changed, 23 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c >> index 0e69aa8..70d5d77 100644 >> --- a/drivers/xen/grant-dma-ops.c >> +++ b/drivers/xen/grant-dma-ops.c >> @@ -66,11 +66,6 @@ static struct xen_grant_dma_data *find_xen_grant_dma_data(struct device *dev) >> * Such a DMA address is formed by using the grant reference as a frame >> * number and setting the highest address bit (this bit is for the backend >> * to be able to distinguish it from e.g. a mmio address). >> - * >> - * Note that for now we hard wire dom0 to be the backend domain. In order >> - * to support any domain as backend we'd need to add a way to communicate >> - * the domid of this backend, e.g. via Xenstore, via the PCI-device's >> - * config space or DT/ACPI. >> */ >> static void *xen_grant_dma_alloc(struct device *dev, size_t size, >> dma_addr_t *dma_handle, gfp_t gfp, >> @@ -277,6 +272,16 @@ static const struct dma_map_ops xen_grant_dma_ops = { >> .dma_supported = xen_grant_dma_supported, >> }; >> >> +bool xen_is_grant_dma_device(struct device *dev) >> +{ >> + /* XXX Handle only DT devices for now */ >> + if (!dev->of_node) >> + return false; >> + >> + return of_property_read_bool(dev->of_node, "xen,dev-domid"); >> +} >> +EXPORT_SYMBOL_GPL(xen_is_grant_dma_device); >> + >> void xen_grant_setup_dma_ops(struct device *dev) >> { >> struct xen_grant_dma_data *data; >> @@ -288,8 +293,14 @@ void xen_grant_setup_dma_ops(struct device *dev) >> return; >> } >> >> - /* XXX The dom0 is hardcoded as the backend domain for now */ >> - dev_domid = 0; >> + /* XXX ACPI and PCI devices unsupported for now */ >> + if (dev_is_pci(dev) || !dev->of_node) >> + goto err; > I think we can remove the "dev_is_pci" check, right? I think, yes (at least for now). I will remove the inclusion of #include <linux/pci.h> as well. > > >> + if (of_property_read_u32(dev->of_node, "xen,dev-domid", &dev_domid)) { >> + dev_err(dev, "xen,dev-domid property is not present\n"); >> + goto err; >> + } >> >> data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); >> if (!data) { >> diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h >> index 4f9fad5..62be9dc 100644 >> --- a/include/xen/xen-ops.h >> +++ b/include/xen/xen-ops.h >> @@ -223,10 +223,15 @@ static inline void xen_preemptible_hcall_end(void) { } >> >> #ifdef CONFIG_XEN_GRANT_DMA_OPS >> void xen_grant_setup_dma_ops(struct device *dev); >> +bool xen_is_grant_dma_device(struct device *dev); >> #else >> static inline void xen_grant_setup_dma_ops(struct device *dev) >> { >> } >> +static inline bool xen_is_grant_dma_device(struct device *dev) >> +{ >> + return false; >> +} >> #endif /* CONFIG_XEN_GRANT_DMA_OPS */ >> >> #endif /* INCLUDE_XEN_OPS_H */ >> -- >> 2.7.4 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>
diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c index 0e69aa8..70d5d77 100644 --- a/drivers/xen/grant-dma-ops.c +++ b/drivers/xen/grant-dma-ops.c @@ -66,11 +66,6 @@ static struct xen_grant_dma_data *find_xen_grant_dma_data(struct device *dev) * Such a DMA address is formed by using the grant reference as a frame * number and setting the highest address bit (this bit is for the backend * to be able to distinguish it from e.g. a mmio address). - * - * Note that for now we hard wire dom0 to be the backend domain. In order - * to support any domain as backend we'd need to add a way to communicate - * the domid of this backend, e.g. via Xenstore, via the PCI-device's - * config space or DT/ACPI. */ static void *xen_grant_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, @@ -277,6 +272,16 @@ static const struct dma_map_ops xen_grant_dma_ops = { .dma_supported = xen_grant_dma_supported, }; +bool xen_is_grant_dma_device(struct device *dev) +{ + /* XXX Handle only DT devices for now */ + if (!dev->of_node) + return false; + + return of_property_read_bool(dev->of_node, "xen,dev-domid"); +} +EXPORT_SYMBOL_GPL(xen_is_grant_dma_device); + void xen_grant_setup_dma_ops(struct device *dev) { struct xen_grant_dma_data *data; @@ -288,8 +293,14 @@ void xen_grant_setup_dma_ops(struct device *dev) return; } - /* XXX The dom0 is hardcoded as the backend domain for now */ - dev_domid = 0; + /* XXX ACPI and PCI devices unsupported for now */ + if (dev_is_pci(dev) || !dev->of_node) + goto err; + + if (of_property_read_u32(dev->of_node, "xen,dev-domid", &dev_domid)) { + dev_err(dev, "xen,dev-domid property is not present\n"); + goto err; + } data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) { diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index 4f9fad5..62be9dc 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -223,10 +223,15 @@ static inline void xen_preemptible_hcall_end(void) { } #ifdef CONFIG_XEN_GRANT_DMA_OPS void xen_grant_setup_dma_ops(struct device *dev); +bool xen_is_grant_dma_device(struct device *dev); #else static inline void xen_grant_setup_dma_ops(struct device *dev) { } +static inline bool xen_is_grant_dma_device(struct device *dev) +{ + return false; +} #endif /* CONFIG_XEN_GRANT_DMA_OPS */ #endif /* INCLUDE_XEN_OPS_H */