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| author | Juergen Gross <jgross@suse.com> | 2022-06-22 08:38:38 +0200 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2022-08-01 07:43:03 +0200 |
| commit | 251e90e7e346a23742b90e2c4db19d322e071d99 (patch) | |
| tree | c4c3477288ae1ab03b0933fbeeaff78020c1b63f /drivers/xen | |
| parent | a870544ca9d215449e91ebc01e35d80b23151c78 (diff) | |
| download | linux-251e90e7e346a23742b90e2c4db19d322e071d99.tar.gz | |
xen: don't require virtio with grants for non-PV guests
Commit fa1f57421e0b ("xen/virtio: Enable restricted memory access using
Xen grant mappings") introduced a new requirement for using virtio
devices: the backend now needs to support the VIRTIO_F_ACCESS_PLATFORM
feature.
This is an undue requirement for non-PV guests, as those can be operated
with existing backends without any problem, as long as those backends
are running in dom0.
Per default allow virtio devices without grant support for non-PV
guests.
On Arm require VIRTIO_F_ACCESS_PLATFORM for devices having been listed
in the device tree to use grants.
Add a new config item to always force use of grants for virtio.
Fixes: fa1f57421e0b ("xen/virtio: Enable restricted memory access using Xen grant mappings")
Reported-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 guest using Xen
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20220622063838.8854-4-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/xen/grant-dma-ops.c | 10 |
2 files changed, 19 insertions, 0 deletions
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index bfd5f4f706bcc0..a65bd92121a5d8 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -355,4 +355,13 @@ config XEN_VIRTIO If in doubt, say n. +config XEN_VIRTIO_FORCE_GRANT + bool "Require Xen virtio support to use grants" + depends on XEN_VIRTIO + help + Require virtio for Xen guests to use grant mappings. + This will avoid the need to give the backend the right to map all + of the guest memory. This will need support on the backend side + (e.g. qemu or kernel, depending on the virtio device types used). + endmenu diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c index fc01424840017e..8973fc1e9cccd2 100644 --- a/drivers/xen/grant-dma-ops.c +++ b/drivers/xen/grant-dma-ops.c @@ -12,6 +12,8 @@ #include <linux/of.h> #include <linux/pfn.h> #include <linux/xarray.h> +#include <linux/virtio_anchor.h> +#include <linux/virtio.h> #include <xen/xen.h> #include <xen/xen-ops.h> #include <xen/grant_table.h> @@ -287,6 +289,14 @@ bool xen_is_grant_dma_device(struct device *dev) return has_iommu; } +bool xen_virtio_mem_acc(struct virtio_device *dev) +{ + if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT)) + return true; + + return xen_is_grant_dma_device(dev->dev.parent); +} + void xen_grant_setup_dma_ops(struct device *dev) { struct xen_grant_dma_data *data; |