Messages in this thread Patch in this message | | | Subject | Re: [PATCH V1 3/6] xen/virtio: Add option to restrict memory access under Xen | From | Oleksandr <> | Date | Sat, 23 Apr 2022 10:05:22 +0300 |
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On 23.04.22 02:00, Stefano Stabellini wrote:
Hello Stefano
> On Fri, 22 Apr 2022, Oleksandr Tyshchenko wrote: >> From: Juergen Gross <jgross@suse.com> >> >> Introduce Xen grant DMA-mapping layer which contains special DMA-mapping >> routines for providing grant references as DMA addresses to be used by >> frontends (e.g. virtio) in Xen guests. >> >> In order to support virtio in Xen guests add a config option XEN_VIRTIO >> enabling the user to specify whether in all Xen guests virtio should >> be able to access memory via Xen grant mappings only on the host side. >> >> As this also requires providing arch_has_restricted_virtio_memory_access >> implementation, switch from a pure stub to a real function on Arm >> and combine with existing implementation for the SEV guests on x86. >> >> Add the needed functionality by providing a special set of DMA ops >> handling the needed grant operations for the I/O pages. >> >> Signed-off-by: Juergen Gross <jgross@suse.com> >> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > There are a couple of minor things that checkpatch.pl reports,
Thank you for pointing this out, my fault.
> but aside > from those the patch looks fine to me.
good
The attached diff to be squashed for the new version. One thing remains:
checkpatch.pl says regarding drivers/xen/grant-dma-ops.c:
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating? #151: new file mode 100644
Which, I assume, this is not an issue as new file falls under XEN HYPERVISOR INTERFACE maintainership?
scripts/get_maintainer.pl -f drivers/xen/grant-dma-ops.c Boris Ostrovsky <boris.ostrovsky@oracle.com> (supporter:XEN HYPERVISOR INTERFACE) Juergen Gross <jgross@suse.com> (supporter:XEN HYPERVISOR INTERFACE) Stefano Stabellini <sstabellini@kernel.org> (reviewer:XEN HYPERVISOR INTERFACE) xen-devel@lists.xenproject.org (moderated list:XEN HYPERVISOR INTERFACE) linux-kernel@vger.kernel.org (open list)
[snip]
-- Regards,
Oleksandr Tyshchenko
From 8d36fc5a3604a69848c300a42f1a78f8ace41829 Mon Sep 17 00:00:00 2001 From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Date: Sat, 23 Apr 2022 09:23:04 +0300 Subject: [PATCH] fixup
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> --- drivers/xen/Kconfig | 2 ++ drivers/xen/grant-dma-ops.c | 21 ++++++++++++--------- 2 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index b95581f..1727337 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -350,4 +350,6 @@ config XEN_VIRTIO guest type this will require special support on the backend side (qemu or kernel, depending on the virtio device types used). + If in doubt, say n. + endmenu diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c index 70d5d77..b9d93d7 100644 --- a/drivers/xen/grant-dma-ops.c +++ b/drivers/xen/grant-dma-ops.c @@ -139,7 +139,7 @@ static struct page *xen_grant_dma_alloc_pages(struct device *dev, size_t size, enum dma_data_direction dir, gfp_t gfp) { - WARN_ONCE(1, "xen_grant_dma_alloc_pages size %zu\n", size); + WARN_ONCE(1, "%s: size %zu\n", __func__, size); return NULL; } @@ -147,7 +147,7 @@ static void xen_grant_dma_free_pages(struct device *dev, size_t size, struct page *vaddr, dma_addr_t dma_handle, enum dma_data_direction dir) { - WARN_ONCE(1, "xen_grant_dma_free_pages size %zu\n", size); + WARN_ONCE(1, "%s: size %zu\n", __func__, size); } static dma_addr_t xen_grant_dma_map_page(struct device *dev, struct page *page, @@ -160,7 +160,8 @@ static dma_addr_t xen_grant_dma_map_page(struct device *dev, struct page *page, grant_ref_t grant; dma_addr_t dma_handle; - BUG_ON(dir == DMA_NONE); + if (WARN_ON(dir == DMA_NONE)) + return DMA_MAPPING_ERROR; data = find_xen_grant_dma_data(dev); if (!data) @@ -190,7 +191,8 @@ static void xen_grant_dma_unmap_page(struct device *dev, dma_addr_t dma_handle, unsigned int i, n_pages = PFN_UP(size); grant_ref_t grant; - BUG_ON(dir == DMA_NONE); + if (WARN_ON(dir == DMA_NONE)) + return; data = find_xen_grant_dma_data(dev); if (!data) @@ -219,7 +221,8 @@ static void xen_grant_dma_unmap_sg(struct device *dev, struct scatterlist *sg, struct scatterlist *s; unsigned int i; - BUG_ON(dir == DMA_NONE); + if (WARN_ON(dir == DMA_NONE)) + return; for_each_sg(sg, s, nents, i) xen_grant_dma_unmap_page(dev, s->dma_address, sg_dma_len(s), dir, @@ -233,7 +236,8 @@ static int xen_grant_dma_map_sg(struct device *dev, struct scatterlist *sg, struct scatterlist *s; unsigned int i; - BUG_ON(dir == DMA_NONE); + if (WARN_ON(dir == DMA_NONE)) + return -EINVAL; for_each_sg(sg, s, nents, i) { s->dma_address = xen_grant_dma_map_page(dev, sg_page(s), s->offset, @@ -303,10 +307,9 @@ void xen_grant_setup_dma_ops(struct device *dev) } data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); - if (!data) { - dev_err(dev, "Сannot allocate Xen grant DMA data\n"); + if (!data) goto err; - } + data->dev_domid = dev_domid; data->dev = dev; -- 2.7.4
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