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[Qemu-devel] [PATCH v2 21/42] ivshmem: Clean up MSI-X conditions
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH v2 21/42] ivshmem: Clean up MSI-X conditions |
Date: |
Mon, 7 Mar 2016 20:25:33 +0100 |
There are three predicates related to MSI-X:
* ivshmem_has_feature(s, IVSHMEM_MSI) is true unless the non-MSI-X
variant of the device is selected with msi=off.
* msix_present() is true when the device has the PCI capability MSI-X.
It's initially false, and becomes true during successful realize of
the MSI-X variant of the device. Thus, it's the same as
ivshmem_has_feature(s, IVSHMEM_MSI) for realized devices.
* msix_enabled() is true when msix_present() is true and guest software
has enabled MSI-X.
Code that differs between the non-MSI-X and the MSI-X variant of the
device needs to be guarded by ivshmem_has_feature(s, IVSHMEM_MSI) or
by msix_present(), except the latter works only for realized devices.
Code that depends on whether MSI-X is in use needs to be guarded with
msix_enabled().
Code review led me to two minor messes:
* ivshmem_vector_notify() calls msix_notify() even when
!msix_enabled(), unlike most other MSI-X-capable devices. As far as
I can tell, msix_notify() does nothing when !msix_enabled(). Add
the guard anyway.
* Most callers of ivshmem_use_msix() guard it with
ivshmem_has_feature(s, IVSHMEM_MSI). Not necessary, because
ivshmem_use_msix() does nothing when !msix_present(). That's
ivshmem's only use of msix_present(), though. Rename
ivshmem_use_msix() to ivshmem_vector_use(), replace msix_present()
by ivshmem_has_feature() there, and drop the redundant guards.
Signed-off-by: Markus Armbruster <address@hidden>
---
hw/misc/ivshmem.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index 7191914..cfea151 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -274,7 +274,9 @@ static void ivshmem_vector_notify(void *opaque)
IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, vector);
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
- msix_notify(pdev, vector);
+ if (msix_enabled(pdev)) {
+ msix_notify(pdev, vector);
+ }
} else {
ivshmem_IntrStatus_write(s, 1);
}
@@ -712,13 +714,12 @@ static void ivshmem_check_version(void *opaque, const
uint8_t * buf, int size)
/* Select the MSI-X vectors used by device.
* ivshmem maps events to vectors statically, so
* we just enable all vectors on init and after reset. */
-static void ivshmem_use_msix(IVShmemState * s)
+static void ivshmem_vector_use(IVShmemState *s)
{
PCIDevice *d = PCI_DEVICE(s);
int i;
- IVSHMEM_DPRINTF("%s, msix present: %d\n", __func__, msix_present(d));
- if (!msix_present(d)) {
+ if (!ivshmem_has_feature(s, IVSHMEM_MSI)) {
return;
}
@@ -733,7 +734,7 @@ static void ivshmem_reset(DeviceState *d)
s->intrstatus = 0;
s->intrmask = 0;
- ivshmem_use_msix(s);
+ ivshmem_vector_use(s);
}
static int ivshmem_setup_interrupts(IVShmemState *s)
@@ -747,9 +748,9 @@ static int ivshmem_setup_interrupts(IVShmemState *s)
}
IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
- ivshmem_use_msix(s);
}
+ ivshmem_vector_use(s);
return 0;
}
@@ -1034,12 +1035,7 @@ static int ivshmem_pre_load(void *opaque)
static int ivshmem_post_load(void *opaque, int version_id)
{
- IVShmemState *s = opaque;
-
- if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
- ivshmem_use_msix(s);
- }
-
+ ivshmem_vector_use(opaque);
return 0;
}
@@ -1067,11 +1063,11 @@ static int ivshmem_load_old(QEMUFile *f, void *opaque,
int version_id)
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
msix_load(pdev, f);
- ivshmem_use_msix(s);
} else {
s->intrstatus = qemu_get_be32(f);
s->intrmask = qemu_get_be32(f);
}
+ ivshmem_vector_use(s);
return 0;
}
--
2.4.3
- [Qemu-devel] [PATCH v2 13/42] ivshmem: Add missing newlines to debug printfs, (continued)
- [Qemu-devel] [PATCH v2 13/42] ivshmem: Add missing newlines to debug printfs, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 01/42] exec: Fix memory allocation when memory path names new file, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 09/42] ivshmem-test: Improve test case /ivshmem/single, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 14/42] ivshmem: Compile debug prints unconditionally to prevent bit-rot, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 08/42] tests/libqos/pci-pc: Fix qpci_pc_iomap() to map BARs aligned, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 19/42] ivshmem: Failed realize() can leave migration blocker behind, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 02/42] exec: Fix memory allocation when memory path isn't on hugetlbfs, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 21/42] ivshmem: Clean up MSI-X conditions,
Markus Armbruster <=
- [Qemu-devel] [PATCH v2 03/42] target-ppc: Document TOCTTOU in hugepage support, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 06/42] qemu-doc: Fix ivshmem huge page example, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 35/42] ivshmem: Inline check_shm_size() into its only caller, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 20/42] ivshmem: Clean up register callbacks, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 05/42] ivshmem-server: Don't overload POSIX shmem and file name, Markus Armbruster, 2016/03/07