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authorLinus Torvalds <torvalds@linux-foundation.org>2016-04-07 16:20:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-04-07 16:20:40 -0700
commitd3436a1d03f9a416d8bedd968f16296e0140adcb (patch)
tree6809a3acc09cafafa4df0646154eb990eeccaab6
parent741f37b8ccf10b3f9976f7e55b703af8087f182a (diff)
parentc00bbcf8628969e103d4a7b351a53746f1025576 (diff)
downloadlinux-sh-d3436a1d03f9a416d8bedd968f16296e0140adcb.tar.gz
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio/qemu fixes from Michael S Tsirkin: "A couple of fixes for virtio and for the new QEMU fw cfg driver" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio: add VIRTIO_CONFIG_S_NEEDS_RESET device status bit MAINTAINERS: add entry for QEMU firmware: qemu_fw_cfg.c: hold ACPI global lock during device access virtio: virtio 1.0 cs04 spec compliance for reset qemu_fw_cfg: don't leak kobj on init error
-rw-r--r--MAINTAINERS7
-rw-r--r--drivers/firmware/qemu_fw_cfg.c24
-rw-r--r--drivers/virtio/virtio_pci_modern.c11
-rw-r--r--include/uapi/linux/virtio_config.h2
4 files changed, 40 insertions, 4 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index 40eb1dbe2ae5..d8c901bbec89 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9142,6 +9142,13 @@ T: git git://github.com/KrasnikovEugene/wcn36xx.git
S: Supported
F: drivers/net/wireless/ath/wcn36xx/
+QEMU MACHINE EMULATOR AND VIRTUALIZER SUPPORT
+M: Gabriel Somlo <somlo@cmu.edu>
+M: "Michael S. Tsirkin" <mst@redhat.com>
+L: qemu-devel@nongnu.org
+S: Maintained
+F: drivers/firmware/qemu_fw_cfg.c
+
RADOS BLOCK DEVICE (RBD)
M: Ilya Dryomov <idryomov@gmail.com>
M: Sage Weil <sage@redhat.com>
diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
index fedbff55a7f3..815c4a5cae54 100644
--- a/drivers/firmware/qemu_fw_cfg.c
+++ b/drivers/firmware/qemu_fw_cfg.c
@@ -77,12 +77,28 @@ static inline u16 fw_cfg_sel_endianness(u16 key)
static inline void fw_cfg_read_blob(u16 key,
void *buf, loff_t pos, size_t count)
{
+ u32 glk;
+ acpi_status status;
+
+ /* If we have ACPI, ensure mutual exclusion against any potential
+ * device access by the firmware, e.g. via AML methods:
+ */
+ status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk);
+ if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) {
+ /* Should never get here */
+ WARN(1, "fw_cfg_read_blob: Failed to lock ACPI!\n");
+ memset(buf, 0, count);
+ return;
+ }
+
mutex_lock(&fw_cfg_dev_lock);
iowrite16(fw_cfg_sel_endianness(key), fw_cfg_reg_ctrl);
while (pos-- > 0)
ioread8(fw_cfg_reg_data);
ioread8_rep(fw_cfg_reg_data, buf, count);
mutex_unlock(&fw_cfg_dev_lock);
+
+ acpi_release_global_lock(glk);
}
/* clean up fw_cfg device i/o */
@@ -727,12 +743,18 @@ device_param_cb(mmio, &fw_cfg_cmdline_param_ops, NULL, S_IRUSR);
static int __init fw_cfg_sysfs_init(void)
{
+ int ret;
+
/* create /sys/firmware/qemu_fw_cfg/ top level directory */
fw_cfg_top_ko = kobject_create_and_add("qemu_fw_cfg", firmware_kobj);
if (!fw_cfg_top_ko)
return -ENOMEM;
- return platform_driver_register(&fw_cfg_sysfs_driver);
+ ret = platform_driver_register(&fw_cfg_sysfs_driver);
+ if (ret)
+ fw_cfg_kobj_cleanup(fw_cfg_top_ko);
+
+ return ret;
}
static void __exit fw_cfg_sysfs_exit(void)
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index f6f28cc7eb45..e76bd91a29da 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -17,6 +17,7 @@
*
*/
+#include <linux/delay.h>
#define VIRTIO_PCI_NO_LEGACY
#include "virtio_pci_common.h"
@@ -271,9 +272,13 @@ static void vp_reset(struct virtio_device *vdev)
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* 0 status means a reset. */
vp_iowrite8(0, &vp_dev->common->device_status);
- /* Flush out the status write, and flush in device writes,
- * including MSI-X interrupts, if any. */
- vp_ioread8(&vp_dev->common->device_status);
+ /* After writing 0 to device_status, the driver MUST wait for a read of
+ * device_status to return 0 before reinitializing the device.
+ * This will flush out the status write, and flush in device writes,
+ * including MSI-X interrupts, if any.
+ */
+ while (vp_ioread8(&vp_dev->common->device_status))
+ msleep(1);
/* Flush pending VQ/configuration callbacks. */
vp_synchronize_vectors(vdev);
}
diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h
index c18264df9504..4cb65bbfa654 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h
@@ -40,6 +40,8 @@
#define VIRTIO_CONFIG_S_DRIVER_OK 4
/* Driver has finished configuring features */
#define VIRTIO_CONFIG_S_FEATURES_OK 8
+/* Device entered invalid state, driver must reset it */
+#define VIRTIO_CONFIG_S_NEEDS_RESET 0x40
/* We've given up on this device. */
#define VIRTIO_CONFIG_S_FAILED 0x80