From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52460) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ymgo4-0007CF-Vu for qemu-devel@nongnu.org; Mon, 27 Apr 2015 07:02:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ymgo0-0007Eh-OJ for qemu-devel@nongnu.org; Mon, 27 Apr 2015 07:02:32 -0400 Date: Mon, 27 Apr 2015 13:02:24 +0200 From: "Michael S. Tsirkin" Message-ID: <20150427130035-mutt-send-email-mst@redhat.com> References: <1429770109-23873-1-git-send-email-jasowang@redhat.com> <1429770109-23873-16-git-send-email-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1429770109-23873-16-git-send-email-jasowang@redhat.com> Subject: Re: [Qemu-devel] [PATCH V7 15/16] virtio-pci: increase the maximum number of virtqueues to 513 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jason Wang Cc: Paolo Bonzini , Alexander Graf , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Richard Henderson On Thu, Apr 23, 2015 at 02:21:48PM +0800, Jason Wang wrote: > This patch increases the maximum number of virtqueues for pci from 64 > to 513. This will allow booting a virtio-net-pci device with 256 queue > pairs on recent Linux host (which supports up to 256 tuntap queue pairs). > > To keep migration compatibility, 64 was kept for legacy machine > types. This is because qemu in fact allows guest to probe the limit of > virtqueues through trying to set queue_sel. So for legacy machine > type, we should make sure setting queue_sel to more than 63 won't > make effect. This isn't a documented interface, and no guest that I know of does this. Accordingly, I think we should drop everything except the hw/virtio/virtio-pci.c change. > Cc: Paolo Bonzini > Cc: Richard Henderson > Cc: Michael S. Tsirkin > Cc: Alexander Graf > Cc: qemu-ppc@nongnu.org > Signed-off-by: Jason Wang > --- > hw/i386/pc_piix.c | 5 +++++ > hw/i386/pc_q35.c | 5 +++++ > hw/ppc/spapr.c | 5 +++++ > hw/virtio/virtio-pci.c | 6 +++++- > 4 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c > index 212e263..6e098ce 100644 > --- a/hw/i386/pc_piix.c > +++ b/hw/i386/pc_piix.c > @@ -49,6 +49,7 @@ > #include "hw/acpi/acpi.h" > #include "cpu.h" > #include "qemu/error-report.h" > +#include "hw/virtio/virtio-bus.h" > #ifdef CONFIG_XEN > # include > #endif > @@ -312,6 +313,10 @@ static void pc_init_pci(MachineState *machine) > > static void pc_compat_2_3(MachineState *machine) > { > + ObjectClass *klass = object_class_by_name("virtio-pci-bus"); > + VirtioBusClass *k = VIRTIO_BUS_CLASS(klass); > + > + k->queue_max = 64; > } > > static void pc_compat_2_2(MachineState *machine) > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c > index e67f2de..ff7c414 100644 > --- a/hw/i386/pc_q35.c > +++ b/hw/i386/pc_q35.c > @@ -45,6 +45,7 @@ > #include "hw/usb.h" > #include "hw/cpu/icc_bus.h" > #include "qemu/error-report.h" > +#include "include/hw/virtio/virtio-bus.h" > > /* ICH9 AHCI has 6 ports */ > #define MAX_SATA_PORTS 6 > @@ -291,6 +292,10 @@ static void pc_q35_init(MachineState *machine) > > static void pc_compat_2_3(MachineState *machine) > { > + ObjectClass *klass = object_class_by_name("virtio-pci-bus"); > + VirtioBusClass *k = VIRTIO_BUS_CLASS(klass); > + > + k->queue_max = 64; > } > > static void pc_compat_2_2(MachineState *machine) > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 8e43aa2..ee8f6a3 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -50,6 +50,7 @@ > #include "hw/pci/pci.h" > #include "hw/scsi/scsi.h" > #include "hw/virtio/virtio-scsi.h" > +#include "hw/virtio/virtio-bus.h" > > #include "exec/address-spaces.h" > #include "hw/usb.h" > @@ -1827,6 +1828,10 @@ static const TypeInfo spapr_machine_info = { > > static void spapr_compat_2_3(Object *obj) > { > + ObjectClass *klass = object_class_by_name("virtio-pci-bus"); > + VirtioBusClass *k = VIRTIO_BUS_CLASS(klass); > + > + k->queue_max = 64; > } > > static void spapr_compat_2_2(Object *obj) > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 7d01500..c510cb7 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -42,7 +42,11 @@ > * configuration space */ > #define VIRTIO_PCI_CONFIG_SIZE(dev) VIRTIO_PCI_CONFIG_OFF(msix_enabled(dev)) > > -#define VIRTIO_PCI_QUEUE_MAX 64 > +/* The number was chose to be greater than both the the number of max > + * vcpus supported by host and the number of max tuntap queues support > + * by host and also leave some spaces for future. > + */ > +#define VIRTIO_PCI_QUEUE_MAX 1024 > > static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size, > VirtIOPCIProxy *dev); > -- > 2.1.0