[v5,2/2] virtio: fix PCI config err handling
diff mbox series

Message ID 20180827165240.28322-2-bluca@debian.org
State Superseded, archived
Delegated to: Thomas Monjalon
Headers show
Series
  • [v5,1/2] bus/pci: harmonize and document rte_pci_read_config return value
Related show

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Luca Boccassi Aug. 27, 2018, 4:52 p.m. UTC
From: Brian Russell <brussell@brocade.com>

In virtio_read_caps and vtpci_msix_detect, rte_pci_read_config returns
the number of bytes read from PCI config or < 0 on error.
If less than the expected number of bytes are read then log the
failure and return rather than carrying on with garbage.

Fixes: 6ba1f63b5ab0 ("virtio: support specification 1.0")

Signed-off-by: Brian Russell <brussell@brocade.com>
Signed-off-by: Luca Boccassi <bluca@debian.org>
---
v2: handle additional rte_pci_read_config incomplete reads
v3: do not handle rte_pci_read_config of virtio cap, added in v2,
    as it's less clear what the right thing to do there is
v4: do a more robust check - first check what the vendor is, and
    skip the cap entirely if it's not what we are looking for.
v5: fetch only 2 flags bytes if the vndr is PCI_CAP_ID_MSIX

 drivers/net/virtio/virtio_pci.c | 66 ++++++++++++++++++++++++---------
 1 file changed, 49 insertions(+), 17 deletions(-)

Comments

Tiwei Bie Aug. 28, 2018, 6:43 a.m. UTC | #1
I just noticed the title. It should be "net/virtio: xxx",
instead of "virtio: xxx".

On Mon, Aug 27, 2018 at 05:52:40PM +0100, Luca Boccassi wrote:
[...]
> +			ret = rte_pci_read_config(dev, &flags, sizeof(flags),
> +					pos + sizeof(cap));
> +			if (ret != sizeof(flags)) {
> +				PMD_INIT_LOG(DEBUG,
> +					     "failed to read pci cap at pos:"
> +					     " %lx ret %d", pos + sizeof(cap),
> +					     ret);

In file included from drivers/net/virtio/virtio_pci.c:15:0:
drivers/net/virtio/virtio_pci.c: In function ‘vtpci_msix_detect’:
drivers/net/virtio/virtio_logs.h:13:3: error: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 5 has type ‘unsigned int’ [-Werror=format=]
   "%s(): " fmt "\n", __func__, ##args)
   ^
drivers/net/virtio/virtio_pci.c:737:5: note: in expansion of macro ‘PMD_INIT_LOG’
     PMD_INIT_LOG(DEBUG,
     ^
cc1: all warnings being treated as errors

I got above build issues in 32bit build.


Apart from that,

Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>

Thanks!
Luca Boccassi Aug. 28, 2018, 10:14 a.m. UTC | #2
On Tue, 2018-08-28 at 14:43 +0800, Tiwei Bie wrote:
> I just noticed the title. It should be "net/virtio: xxx",
> instead of "virtio: xxx".

Fixed

> On Mon, Aug 27, 2018 at 05:52:40PM +0100, Luca Boccassi wrote:
> [...]
> > +			ret = rte_pci_read_config(dev, &flags,
> > sizeof(flags),
> > +					pos + sizeof(cap));
> > +			if (ret != sizeof(flags)) {
> > +				PMD_INIT_LOG(DEBUG,
> > +					     "failed to read pci
> > cap at pos:"
> > +					     " %lx ret %d", pos +
> > sizeof(cap),
> > +					     ret);
> 
> In file included from drivers/net/virtio/virtio_pci.c:15:0:
> drivers/net/virtio/virtio_pci.c: In function ‘vtpci_msix_detect’:
> drivers/net/virtio/virtio_logs.h:13:3: error: format ‘%lx’ expects
> argument of type ‘long unsigned int’, but argument 5 has type
> ‘unsigned int’ [-Werror=format=]
>    "%s(): " fmt "\n", __func__, ##args)
>    ^
> drivers/net/virtio/virtio_pci.c:737:5: note: in expansion of macro
> ‘PMD_INIT_LOG’
>      PMD_INIT_LOG(DEBUG,
>      ^
> cc1: all warnings being treated as errors
> 
> I got above build issues in 32bit build.
> 
> 
> Apart from that,
> 
> Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
> 
> Thanks!

So the 32 and 64 bit builds want opposite things, due to the sizeof
type. I changed it to avoid sizeof and just calculate it like in every
other prints of these functions to avoid the issue.

Patch
diff mbox series

diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
index 6bd22e54a6..e900254a12 100644
--- a/drivers/net/virtio/virtio_pci.c
+++ b/drivers/net/virtio/virtio_pci.c
@@ -567,16 +567,18 @@  virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
 	}
 
 	ret = rte_pci_read_config(dev, &pos, 1, PCI_CAPABILITY_LIST);
-	if (ret < 0) {
-		PMD_INIT_LOG(DEBUG, "failed to read pci capability list");
+	if (ret != 1) {
+		PMD_INIT_LOG(DEBUG,
+			     "failed to read pci capability list, ret %d", ret);
 		return -1;
 	}
 
 	while (pos) {
-		ret = rte_pci_read_config(dev, &cap, sizeof(cap), pos);
-		if (ret < 0) {
-			PMD_INIT_LOG(ERR,
-				"failed to read pci cap at pos: %x", pos);
+		ret = rte_pci_read_config(dev, &cap, 2, pos);
+		if (ret != 2) {
+			PMD_INIT_LOG(DEBUG,
+				     "failed to read pci cap at pos: %x ret %d",
+				     pos, ret);
 			break;
 		}
 
@@ -586,7 +588,16 @@  virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
 			 * 1st byte is cap ID; 2nd byte is the position of next
 			 * cap; next two bytes are the flags.
 			 */
-			uint16_t flags = ((uint16_t *)&cap)[1];
+			uint16_t flags;
+
+			ret = rte_pci_read_config(dev, &flags, sizeof(flags),
+					pos + 2);
+			if (ret != sizeof(flags)) {
+				PMD_INIT_LOG(DEBUG,
+					     "failed to read pci cap at pos:"
+					     " %x ret %d", pos + 2, ret);
+				break;
+			}
 
 			if (flags & PCI_MSIX_ENABLE)
 				hw->use_msix = VIRTIO_MSIX_ENABLED;
@@ -601,6 +612,14 @@  virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
 			goto next;
 		}
 
+		ret = rte_pci_read_config(dev, &cap, sizeof(cap), pos);
+		if (ret != sizeof(cap)) {
+			PMD_INIT_LOG(DEBUG,
+				     "failed to read pci cap at pos: %x ret %d",
+				     pos, ret);
+			break;
+		}
+
 		PMD_INIT_LOG(DEBUG,
 			"[%2x] cfg type: %u, bar: %u, offset: %04x, len: %u",
 			pos, cap.cfg_type, cap.bar, cap.offset, cap.length);
@@ -689,25 +708,38 @@  enum virtio_msix_status
 vtpci_msix_detect(struct rte_pci_device *dev)
 {
 	uint8_t pos;
-	struct virtio_pci_cap cap;
 	int ret;
 
 	ret = rte_pci_read_config(dev, &pos, 1, PCI_CAPABILITY_LIST);
-	if (ret < 0) {
-		PMD_INIT_LOG(DEBUG, "failed to read pci capability list");
+	if (ret != 1) {
+		PMD_INIT_LOG(DEBUG,
+			     "failed to read pci capability list, ret %d", ret);
 		return VIRTIO_MSIX_NONE;
 	}
 
 	while (pos) {
-		ret = rte_pci_read_config(dev, &cap, sizeof(cap), pos);
-		if (ret < 0) {
-			PMD_INIT_LOG(ERR,
-				"failed to read pci cap at pos: %x", pos);
+		uint8_t cap[2];
+
+		ret = rte_pci_read_config(dev, cap, sizeof(cap), pos);
+		if (ret != sizeof(cap)) {
+			PMD_INIT_LOG(DEBUG,
+				     "failed to read pci cap at pos: %x ret %d",
+				     pos, ret);
 			break;
 		}
 
-		if (cap.cap_vndr == PCI_CAP_ID_MSIX) {
-			uint16_t flags = ((uint16_t *)&cap)[1];
+		if (cap[0] == PCI_CAP_ID_MSIX) {
+			uint16_t flags;
+
+			ret = rte_pci_read_config(dev, &flags, sizeof(flags),
+					pos + sizeof(cap));
+			if (ret != sizeof(flags)) {
+				PMD_INIT_LOG(DEBUG,
+					     "failed to read pci cap at pos:"
+					     " %lx ret %d", pos + sizeof(cap),
+					     ret);
+				break;
+			}
 
 			if (flags & PCI_MSIX_ENABLE)
 				return VIRTIO_MSIX_ENABLED;
@@ -715,7 +747,7 @@  vtpci_msix_detect(struct rte_pci_device *dev)
 				return VIRTIO_MSIX_DISABLED;
 		}
 
-		pos = cap.cap_next;
+		pos = cap[1];
 	}
 
 	return VIRTIO_MSIX_NONE;