From: Gerd Hoffmann <kraxel@redhat.com>
To: kevin.tian@intel.com,
Alex Williamson <alex.williamson@redhat.com>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: igvt-g@ml01.01.org, xen-devel@lists.xensource.com,
Gerd Hoffmann <kraxel@redhat.com>,
"open list:All patches CC here" <qemu-devel@nongnu.org>
Subject: [PATCH v4 6/8] igd: revamp host config read
Date: Tue, 8 Mar 2016 15:27:25 +0100 [thread overview]
Message-ID: <1457447247-4865-7-git-send-email-kraxel@redhat.com> (raw)
In-Reply-To: <1457447247-4865-1-git-send-email-kraxel@redhat.com>
Move all work to the host_pci_config_copy helper function,
which we can easily reuse when adding q35 support.
Open sysfs file only once for all values. Use pread.
Proper error handling.
Fix bug: Update config space directly (writing via
pci_default_write_config only works for registers
whitelisted in wmask).
Hmm, this code can hardly ever worked before,
/me wonders what test coverage it had.
With this patch in place igd-passthru=on actually
works, although it still requires root priviledges
because linux refuses to allow non-root users access
pci config space above offset 0x50.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
hw/pci-host/igd.c | 65 ++++++++++++++++++++++---------------------------------
1 file changed, 26 insertions(+), 39 deletions(-)
diff --git a/hw/pci-host/igd.c b/hw/pci-host/igd.c
index 8a8b37b..5c4a008 100644
--- a/hw/pci-host/igd.c
+++ b/hw/pci-host/igd.c
@@ -20,40 +20,33 @@ static const IGDHostInfo igd_host_bridge_infos[] = {
{0xa8, 4}, /* SNB: base of GTT stolen memory */
};
-static int host_pci_config_read(int pos, int len, uint32_t *val)
+static void host_pci_config_copy(PCIDevice *guest, const char *host,
+ const IGDHostInfo *list, int len, Error **errp)
{
- char path[PATH_MAX];
- int config_fd;
- ssize_t size = sizeof(path);
- /* Access real host bridge. */
- int rc = snprintf(path, size, "/sys/bus/pci/devices/%04x:%02x:%02x.%d/%s",
- 0, 0, 0, 0, "config");
- int ret = 0;
+ char *path;
+ int config_fd, rc, i;
- if (rc >= size || rc < 0) {
- return -ENODEV;
- }
-
- config_fd = open(path, O_RDWR);
+ path = g_strdup_printf("/sys/bus/pci/devices/%s/config", host);
+ config_fd = open(path, O_RDONLY);
if (config_fd < 0) {
- return -ENODEV;
+ error_setg_file_open(errp, errno, path);
+ goto out_free;
}
- if (lseek(config_fd, pos, SEEK_SET) != pos) {
- ret = -errno;
- goto out;
+ for (i = 0; i < len; i++) {
+ rc = pread(config_fd, guest->config + list[i].offset,
+ list[i].len, list[i].offset);
+ if (rc != list[i].len) {
+ error_setg_errno(errp, errno, "read %s, offset 0x%x",
+ path, list[i].offset);
+ goto out_close;
+ }
}
- do {
- rc = read(config_fd, (uint8_t *)val, len);
- } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
- if (rc != len) {
- ret = -errno;
- }
-
-out:
+out_close:
close(config_fd);
- return ret;
+out_free:
+ g_free(path);
}
#define IGD_PT_I440FX_CLASS(class) \
@@ -72,9 +65,6 @@ static void igd_pt_i440fx_realize(PCIDevice *pci_dev, Error **errp)
{
IGDPtI440fxClass *k = IGD_PT_I440FX_GET_CLASS(pci_dev);
Error *err = NULL;
- uint32_t val = 0;
- int rc, i, num;
- int pos, len;
k->parent_realize(pci_dev, &err);
if (err != NULL) {
@@ -82,16 +72,13 @@ static void igd_pt_i440fx_realize(PCIDevice *pci_dev, Error **errp)
return;
}
- num = ARRAY_SIZE(igd_host_bridge_infos);
- for (i = 0; i < num; i++) {
- pos = igd_host_bridge_infos[i].offset;
- len = igd_host_bridge_infos[i].len;
- rc = host_pci_config_read(pos, len, &val);
- if (rc) {
- error_setg(errp, "failed to read host config");
- return;
- }
- pci_default_write_config(pci_dev, pos, val, len);
+ host_pci_config_copy(pci_dev, "0000:00:00.0",
+ igd_host_bridge_infos,
+ ARRAY_SIZE(igd_host_bridge_infos),
+ &err);
+ if (err != NULL) {
+ error_propagate(errp, err);
+ return;
}
}
--
1.8.3.1
next prev parent reply other threads:[~2016-03-08 14:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-08 14:27 [PATCH v4 0/8] igd passthrough chipset tweaks Gerd Hoffmann
2016-03-08 14:27 ` [PATCH v4 1/8] pc: remove has_igd_gfx_passthru global Gerd Hoffmann
2016-03-08 14:27 ` [PATCH v4 2/8] pc: move igd support code to igd.c Gerd Hoffmann
2016-03-09 15:08 ` Gerd Hoffmann
2016-03-10 5:56 ` Tian, Kevin
2016-03-10 17:51 ` Kay, Allen M
2016-03-08 14:27 ` [PATCH v4 3/8] igd: switch TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE to realize Gerd Hoffmann
2016-03-08 14:27 ` [PATCH v4 4/8] igd: TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE: call parent realize Gerd Hoffmann
2016-03-08 14:27 ` [PATCH v4 5/8] igd: use defines for standard pci config space offsets Gerd Hoffmann
2016-03-08 14:27 ` Gerd Hoffmann [this message]
2016-03-08 14:27 ` [PATCH v4 7/8] igd: move igd-passthrough-isa-bridge to igd.c too Gerd Hoffmann
2016-03-08 14:27 ` [PATCH v4 8/8] igd: handle igd-passthrough-isa-bridge setup in realize() Gerd Hoffmann
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