On 23.04.22 02:00, Stefano Stabellini wrote:
Hello Stefano
On Fri, 22 Apr 2022, Oleksandr Tyshchenko wrote:
From: Juergen Gross <[email protected]>
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 <[email protected]>
Signed-off-by: Oleksandr Tyshchenko <[email protected]>
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 <[email protected]> (supporter:XEN HYPERVISOR
INTERFACE)
Juergen Gross <[email protected]> (supporter:XEN HYPERVISOR INTERFACE)
Stefano Stabellini <[email protected]> (reviewer:XEN HYPERVISOR
INTERFACE)
[email protected] (moderated list:XEN HYPERVISOR INTERFACE)
[email protected] (open list)
[snip]
--
Regards,
Oleksandr Tyshchenko
>From 8d36fc5a3604a69848c300a42f1a78f8ace41829 Mon Sep 17 00:00:00 2001
From: Oleksandr Tyshchenko <[email protected]>
Date: Sat, 23 Apr 2022 09:23:04 +0300
Subject: [PATCH] fixup
Signed-off-by: Oleksandr Tyshchenko <[email protected]>
---
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
