2:59 p.m.
Virt machine in qemu since v2.3.0 has PCI generic host controller, and can use
PCI devices. This provides performance improvement as well as vhost-net with
irqfd support for virtio-net. However libvirt currently does not allow ARM virt
machine to have PCI devices. This patchset adds the necessary support.
This version is completely reworked and uses different approach.
Changes since v2:
- Correctly model PCI Express bus on the machine. It is now possible to
explicitly specify <address-type='pci'> with attributes. This allows to
attach not only virtio, but any other PCI device to the model.
- Default is not changed and still mmio, for backwards compatibility with
existing installations. PCI bus has to be explicitly specified.
- Check for the capability in correct place, in v2 it actually did not work
Changes since v1:
- Added capability based on qemu version number
- Recognize also "virt-" prefix
Pavel Fedin (3):
Introduce QEMU_CAPS_ARM_VIRT_PCI
Add PCI-Express root to ARM virt machine
Build correct command line for PCI NICs on ARM
src/qemu/qemu_capabilities.c | 5 +++++
src/qemu/qemu_capabilities.h | 1 +
src/qemu/qemu_command.c | 3 ++-
src/qemu/qemu_domain.c | 12 ++++++++----
4 files changed, 16 insertions(+), 5 deletions(-)
--
1.9.5.msysgit.0
2:59 p.m.
New subject: [libvirt] [PATCH v3 1/3] Introduce QEMU_CAPS_ARM_VIRT_PCI
This capability specifies that "virt" machine on ARM has PCI controller.
Enabled when qemu version is at least 2.3.0.
Signed-off-by: Pavel Fedin <p.fedin(a)samsung.com>
---
src/qemu/qemu_capabilities.c | 5 +++++
src/qemu/qemu_capabilities.h | 1 +
2 files changed, 6 insertions(+)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 27686c3..0dc034f 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -287,6 +287,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
"aarch64-off",
"vhost-user-multiqueue", /* 190 */
+ "arm-virt-pci",
);
@@ -3352,6 +3353,10 @@ virQEMUCapsInitQMPMonitor(virQEMUCapsPtr qemuCaps,
qemuCaps->version >= 2003000)
virQEMUCapsSet(qemuCaps, QEMU_CAPS_CPU_AARCH64_OFF);
+ /* 'virt' machine has PCI controller from v2.3.0 onwards */
+ if (qemuCaps->version >= 2003000)
+ virQEMUCapsSet(qemuCaps, QEMU_CAPS_ARM_VIRT_PCI);
+
/* vhost-user supports multi-queue from v2.4.0 onwards,
* but there is no way to query for that capability */
if (qemuCaps->version >= 2004000)
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 30aa504..f4180a8 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -230,6 +230,7 @@ typedef enum {
QEMU_CAPS_DEVICE_PCI_SERIAL = 188, /* -device pci-serial */
QEMU_CAPS_CPU_AARCH64_OFF = 189, /* -cpu ...,aarch64=off */
QEMU_CAPS_VHOSTUSER_MULTIQUEUE = 190, /* vhost-user with -netdev queues= */
+ QEMU_CAPS_ARM_VIRT_PCI = 191, /* ARM 'virt' machine has PCI bus */
QEMU_CAPS_LAST, /* this must always be the last item */
} virQEMUCapsFlags;
--
1.9.5.msysgit.0
9:36 a.m.
New subject: [libvirt] [PATCH v3 1/3] Introduce QEMU_CAPS_ARM_VIRT_PCI
On Mon, Jul 06, 2015 at 15:59:25 +0300, Pavel Fedin wrote:
This capability specifies that "virt" machine on ARM has
PCI controller.
Enabled when qemu version is at least 2.3.0.
Signed-off-by: Pavel Fedin <p.fedin(a)samsung.com>
---
src/qemu/qemu_capabilities.c | 5 +++++
src/qemu/qemu_capabilities.h | 1 +
2 files changed, 6 insertions(+)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 27686c3..0dc034f 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
...
@@ -3352,6 +3353,10 @@ virQEMUCapsInitQMPMonitor(virQEMUCapsPtr
qemuCaps,
qemuCaps->version >= 2003000)
virQEMUCapsSet(qemuCaps, QEMU_CAPS_CPU_AARCH64_OFF);
+ /* 'virt' machine has PCI controller from v2.3.0 onwards */
+ if (qemuCaps->version >= 2003000)
+ virQEMUCapsSet(qemuCaps, QEMU_CAPS_ARM_VIRT_PCI);
Is there a way how we could detect this according to the actual presence
of the PCI bus for the ARM machine? A certain device type that can be
queried rather than relying on a version check.
(see virQEMUCapsObjectTypes[] and other similar arrays in
src/qemu/qemu_caps.c)
Generally the approach is to use a specific device check to set
capabilities for anything where it's possible since it's robust against
backports of given functionality to previous versions.
+
/* vhost-user supports multi-queue from v2.4.0 onwards,
* but there is no way to query for that capability */
if (qemuCaps->version >= 2004000)
Peter
10:25 a.m.
New subject: [libvirt] [PATCH v3 1/3] Introduce QEMU_CAPS_ARM_VIRT_PCI
Hello!
Is there a way how we could detect this according to the actual
presence
of the PCI bus for the ARM machine? A certain device type that can be
queried rather than relying on a version check.
I looked at the code you suggested. As far as i could understand, it actually parses an
output of
"qemu-system-blah -device ?" plus some extras. And this command lists all
devices that this qemu
version knows, and not only what can be attached to a particular machine.
I browsed through the history of qemu patches. Actually, "gpex-pcihost" device
was implemented
together with adding it to 'virt' machine. So, i could query for this flag and
count it as
capability. But - it only says that qemu knows this device in principle. It does not say
that this
device is really a part of virt machine. Will it be acceptable ?
Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia
2:59 p.m.
New subject: [libvirt] [PATCH v3 2/3] Add PCI-Express root to ARM virt machine
Add PCI Express root complex if the corresponding capability is present
Signed-off-by: Pavel Fedin <p.fedin(a)samsung.com>
---
src/qemu/qemu_domain.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index f9bf32c..36f411d 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -981,7 +981,7 @@ virDomainXMLNamespace virQEMUDriverDomainXMLNamespace = {
static int
qemuDomainDefPostParse(virDomainDefPtr def,
virCapsPtr caps,
- void *opaque ATTRIBUTE_UNUSED)
+ void *opaque)
{
bool addDefaultUSB = true;
bool addImplicitSATA = false;
@@ -1030,12 +1030,16 @@ qemuDomainDefPostParse(virDomainDefPtr def,
break;
case VIR_ARCH_ARMV7L:
- addDefaultUSB = false;
- addDefaultMemballoon = false;
- break;
case VIR_ARCH_AARCH64:
addDefaultUSB = false;
addDefaultMemballoon = false;
+ if (STREQ(def->os.machine, "virt") ||
+ STRPREFIX(def->os.machine, "virt-")) {
+ virQEMUDriverPtr driver = opaque;
+ virQEMUCapsPtr qemuCaps =
+ virQEMUCapsCacheLookup(driver->qemuCapsCache, def->emulator);
+ addPCIeRoot = virQEMUCapsGet(qemuCaps, QEMU_CAPS_ARM_VIRT_PCI);
+ }
break;
case VIR_ARCH_PPC64:
--
1.9.5.msysgit.0
9:39 a.m.
New subject: [libvirt] [PATCH v3 2/3] Add PCI-Express root to ARM virt machine
On Mon, Jul 06, 2015 at 15:59:26 +0300, Pavel Fedin wrote:
Add PCI Express root complex if the corresponding capability is
present
Signed-off-by: Pavel Fedin <p.fedin(a)samsung.com>
---
src/qemu/qemu_domain.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index f9bf32c..36f411d 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
...
@@ -1030,12 +1030,16 @@ qemuDomainDefPostParse(virDomainDefPtr def,
break;
case VIR_ARCH_ARMV7L:
- addDefaultUSB = false;
- addDefaultMemballoon = false;
- break;
case VIR_ARCH_AARCH64:
addDefaultUSB = false;
addDefaultMemballoon = false;
+ if (STREQ(def->os.machine, "virt") ||
+ STRPREFIX(def->os.machine, "virt-")) {
+ virQEMUDriverPtr driver = opaque;
+ virQEMUCapsPtr qemuCaps =
+ virQEMUCapsCacheLookup(driver->qemuCapsCache, def->emulator);
+ addPCIeRoot = virQEMUCapsGet(qemuCaps, QEMU_CAPS_ARM_VIRT_PCI);
Is there a way where we would make this configurable? Since the "virt"
machine types use the MMIO bus by default we should make the PCI bus
configurable since not everybody might want to add it actually.
+ }
break;
case VIR_ARCH_PPC64:
--
1.9.5.msysgit.0
Peter
9:51 a.m.
New subject: [libvirt] [PATCH v3 2/3] Add PCI-Express root to ARM virt machine
Hello!
Is there a way where we would make this configurable? Since the
"virt"
machine types use the MMIO bus by default we should make the PCI bus
configurable since not everybody might want to add it actually.
What exactly do you mean? In qemu this is not configurable, it's just there. If you
don't want to
use it, just don't use it. I see no harm done by adding description of it to domain
XML. If you just
add a device, and don't specify <address type='pci'>, it will default to
<address
type='virtio-mmio'> as before. Nothing will change regarding old behavior and
backwards
compatibility.
Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia
4:38 p.m.
New subject: [libvirt] [PATCH v3 2/3] Add PCI-Express root to ARM virt machine
On Tue, Jul 07, 2015 at 10:51:45AM +0300, Pavel Fedin wrote:
Hello!
> Is there a way where we would make this configurable? Since the "virt"
> machine types use the MMIO bus by default we should make the PCI bus
> configurable since not everybody might want to add it actually.
What exactly do you mean? In qemu this is not configurable, it's just there. If you
don't want to
use it, just don't use it. I see no harm done by adding description of it to domain
XML. If you just
add a device, and don't specify <address type='pci'>, it will default
to <address
type='virtio-mmio'> as before. Nothing will change regarding old behavior and
backwards
compatibility.
The domain XML should contain the devices that are there, not just those
the user requested.
Backwards compatibility could break if older libvirt refused to start
the domain with a pcie root. From looking at the code, that does not
seem to be the case.
Jan
2:59 p.m.
New subject: [libvirt] [PATCH v3 3/3] Build correct command line for PCI NICs on ARM
Legacy -net option works correctly only with embedded device models, which
do not require any bus specification. Therefore, we should use -device for
PCI hardware
Signed-off-by: Pavel Fedin <p.fedin(a)samsung.com>
---
src/qemu/qemu_command.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 25a7bc6..983fcdb 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -457,7 +457,8 @@ qemuDomainSupportsNicdev(virDomainDefPtr def,
/* non-virtio ARM nics require legacy -net nic */
if (((def->os.arch == VIR_ARCH_ARMV7L) ||
(def->os.arch == VIR_ARCH_AARCH64)) &&
- net->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_MMIO)
+ net->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_MMIO &&
+ net->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI)
return false;
return true;
--
1.9.5.msysgit.0
3358
days inactive
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days old
8 comments
3 participants
participants (3)
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Ján Tomko -
Pavel Fedin -
Peter Krempa