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[Qemu-devel] [PATCH v3] xen-platform: separate unplugging of NVMe disks
From: |
Paul Durrant |
Subject: |
[Qemu-devel] [PATCH v3] xen-platform: separate unplugging of NVMe disks |
Date: |
Fri, 24 Mar 2017 13:40:25 +0000 |
Commit 090fa1c8 "add support for unplugging NVMe disks..." extended the
existing disk unplug flag to cover NVMe disks as well as IDE and SCSI.
The recent thread on the xen-devel mailing list [1] has highlighted that
this is not desirable behaviour: PV frontends should be able to distinguish
NVMe disks from other types of disk and should have separate control over
whether they are unplugged.
This patch defines a new bit in the unplug mask for this purpose (see Xen
commit [2]) and also tidies up the definitions of, and improves the
comments regarding, the previously exiting bits in the protocol.
[1] https://lists.xen.org/archives/html/xen-devel/2017-03/msg02924.html
[2] http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=1096aa02
Signed-off-by: Paul Durrant <address@hidden>
Reviewed-by: Stefano Stabellini <address@hidden>
--
Cc: Anthony Perard <address@hidden>
v3:
- Updated to reference Xen documentation patch
v2:
- Fix the commit comment
---
hw/i386/xen/xen_platform.c | 47 ++++++++++++++++++++++++++++++++++------------
1 file changed, 35 insertions(+), 12 deletions(-)
diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
index 6010f35..983d532 100644
--- a/hw/i386/xen/xen_platform.c
+++ b/hw/i386/xen/xen_platform.c
@@ -87,10 +87,30 @@ static void log_writeb(PCIXenPlatformState *s, char val)
}
}
-/* Xen Platform, Fixed IOPort */
-#define UNPLUG_ALL_DISKS 1
-#define UNPLUG_ALL_NICS 2
-#define UNPLUG_AUX_IDE_DISKS 4
+/*
+ * Unplug device flags.
+ *
+ * The logic got a little confused at some point in the past but this is
+ * what they do now.
+ *
+ * bit 0: Unplug all IDE and SCSI disks.
+ * bit 1: Unplug all NICs.
+ * bit 2: Unplug IDE disks except primary master. This is overridden if
+ * bit 0 is also present in the mask.
+ * bit 3: Unplug all NVMe disks.
+ *
+ */
+#define _UNPLUG_IDE_SCSI_DISKS 0
+#define UNPLUG_IDE_SCSI_DISKS (1u << _UNPLUG_IDE_SCSI_DISKS)
+
+#define _UNPLUG_ALL_NICS 1
+#define UNPLUG_ALL_NICS (1u << _UNPLUG_ALL_NICS)
+
+#define _UNPLUG_AUX_IDE_DISKS 2
+#define UNPLUG_AUX_IDE_DISKS (1u << _UNPLUG_AUX_IDE_DISKS)
+
+#define _UNPLUG_NVME_DISKS 3
+#define UNPLUG_NVME_DISKS (1u << _UNPLUG_NVME_DISKS)
static void unplug_nic(PCIBus *b, PCIDevice *d, void *o)
{
@@ -111,7 +131,7 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, void
*opaque)
{
uint32_t flags = *(uint32_t *)opaque;
bool aux = (flags & UNPLUG_AUX_IDE_DISKS) &&
- !(flags & UNPLUG_ALL_DISKS);
+ !(flags & UNPLUG_IDE_SCSI_DISKS);
/* We have to ignore passthrough devices */
if (!strcmp(d->name, "xen-pci-passthrough")) {
@@ -124,12 +144,16 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, void
*opaque)
break;
case PCI_CLASS_STORAGE_SCSI:
- case PCI_CLASS_STORAGE_EXPRESS:
if (!aux) {
object_unparent(OBJECT(d));
}
break;
+ case PCI_CLASS_STORAGE_EXPRESS:
+ if (flags & UNPLUG_NVME_DISKS) {
+ object_unparent(OBJECT(d));
+ }
+
default:
break;
}
@@ -147,10 +171,9 @@ static void platform_fixed_ioport_writew(void *opaque,
uint32_t addr, uint32_t v
switch (addr) {
case 0: {
PCIDevice *pci_dev = PCI_DEVICE(s);
- /* Unplug devices. Value is a bitmask of which devices to
- unplug, with bit 0 the disk devices, bit 1 the network
- devices, and bit 2 the non-primary-master IDE devices. */
- if (val & (UNPLUG_ALL_DISKS | UNPLUG_AUX_IDE_DISKS)) {
+ /* Unplug devices. See comment above flag definitions */
+ if (val & (UNPLUG_IDE_SCSI_DISKS | UNPLUG_AUX_IDE_DISKS |
+ UNPLUG_NVME_DISKS)) {
DPRINTF("unplug disks\n");
pci_unplug_disks(pci_dev->bus, val);
}
@@ -338,14 +361,14 @@ static void xen_platform_ioport_writeb(void *opaque,
hwaddr addr,
* If VMDP was to control both disk and LAN it would use 4.
* If it controlled just disk or just LAN, it would use 8 below.
*/
- pci_unplug_disks(pci_dev->bus, UNPLUG_ALL_DISKS);
+ pci_unplug_disks(pci_dev->bus, UNPLUG_IDE_SCSI_DISKS);
pci_unplug_nics(pci_dev->bus);
}
break;
case 8:
switch (val) {
case 1:
- pci_unplug_disks(pci_dev->bus, UNPLUG_ALL_DISKS);
+ pci_unplug_disks(pci_dev->bus, UNPLUG_IDE_SCSI_DISKS);
break;
case 2:
pci_unplug_nics(pci_dev->bus);
--
2.1.4
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