hw/core/machine.c | 3 +++ hw/i386/pc.c | 3 +++ hw/i386/pc_q35.c | 16 ++++++++++++++-- include/hw/boards.h | 3 +++ include/hw/i386/pc.h | 3 +++ 5 files changed, 26 insertions(+), 2 deletions(-)
Backport of QEMU v4.1 commit for stable v4.0.1 release
commit c87759ce876a7a0b17c2bf4f0b964bd51f0ee871
Author: Alex Williamson <alex.williamson@redhat.com>
Date: Tue May 14 14:14:41 2019 -0600
q35: Revert to kernel irqchip
Commit b2fc91db8447 ("q35: set split kernel irqchip as default") changed
the default for the pc-q35-4.0 machine type to use split irqchip, which
turned out to have disasterous effects on vfio-pci INTx support. KVM
resampling irqfds are registered for handling these interrupts, but
these are non-functional in split irqchip mode. We can't simply test
for split irqchip in QEMU as userspace handling of this interrupt is a
significant performance regression versus KVM handling (GeForce GPUs
assigned to Windows VMs are non-functional without forcing MSI mode or
re-enabling kernel irqchip).
The resolution is to revert the change in default irqchip mode in the
pc-q35-4.1 machine and create a pc-q35-4.0.1 machine for the 4.0-stable
branch. The qemu-q35-4.0 machine type should not be used in vfio-pci
configurations for devices requiring legacy INTx support without
explicitly modifying the VM configuration to use kernel irqchip.
Link: https://bugs.launchpad.net/qemu/+bug/1826422
Fixes: b2fc91db8447 ("q35: set split kernel irqchip as default")
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
Same code as v1, just updating the commit log as a formal backport of
the merged 4.1 commit.
hw/core/machine.c | 3 +++
hw/i386/pc.c | 3 +++
hw/i386/pc_q35.c | 16 ++++++++++++++--
include/hw/boards.h | 3 +++
include/hw/i386/pc.h | 3 +++
5 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/hw/core/machine.c b/hw/core/machine.c
index 743fef28982c..5d046a43e3d2 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -24,6 +24,9 @@
#include "hw/pci/pci.h"
#include "hw/mem/nvdimm.h"
+GlobalProperty hw_compat_4_0[] = {};
+const size_t hw_compat_4_0_len = G_N_ELEMENTS(hw_compat_4_0);
+
GlobalProperty hw_compat_3_1[] = {
{ "pcie-root-port", "x-speed", "2_5" },
{ "pcie-root-port", "x-width", "1" },
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index f2c15bf1f2c3..d98b737b8f3b 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -115,6 +115,9 @@ struct hpet_fw_config hpet_cfg = {.count = UINT8_MAX};
/* Physical Address of PVH entry point read from kernel ELF NOTE */
static size_t pvh_start_addr;
+GlobalProperty pc_compat_4_0[] = {};
+const size_t pc_compat_4_0_len = G_N_ELEMENTS(pc_compat_4_0);
+
GlobalProperty pc_compat_3_1[] = {
{ "intel-iommu", "dma-drain", "off" },
{ "Opteron_G3" "-" TYPE_X86_CPU, "rdtscp", "off" },
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 372c6b73bebd..45cc29d1adb7 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -357,7 +357,7 @@ static void pc_q35_machine_options(MachineClass *m)
m->units_per_default_bus = 1;
m->default_machine_opts = "firmware=bios-256k.bin";
m->default_display = "std";
- m->default_kernel_irqchip_split = true;
+ m->default_kernel_irqchip_split = false;
m->no_floppy = 1;
machine_class_allow_dynamic_sysbus_dev(m, TYPE_AMD_IOMMU_DEVICE);
machine_class_allow_dynamic_sysbus_dev(m, TYPE_INTEL_IOMMU_DEVICE);
@@ -365,12 +365,24 @@ static void pc_q35_machine_options(MachineClass *m)
m->max_cpus = 288;
}
-static void pc_q35_4_0_machine_options(MachineClass *m)
+static void pc_q35_4_0_1_machine_options(MachineClass *m)
{
pc_q35_machine_options(m);
m->alias = "q35";
}
+DEFINE_Q35_MACHINE(v4_0_1, "pc-q35-4.0.1", NULL,
+ pc_q35_4_0_1_machine_options);
+
+static void pc_q35_4_0_machine_options(MachineClass *m)
+{
+ pc_q35_4_0_1_machine_options(m);
+ m->default_kernel_irqchip_split = true;
+ m->alias = NULL;
+ compat_props_add(m->compat_props, hw_compat_4_0, hw_compat_4_0_len);
+ compat_props_add(m->compat_props, pc_compat_4_0, pc_compat_4_0_len);
+}
+
DEFINE_Q35_MACHINE(v4_0, "pc-q35-4.0", NULL,
pc_q35_4_0_machine_options);
diff --git a/include/hw/boards.h b/include/hw/boards.h
index e231860666a1..fe1885cbffa0 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -293,6 +293,9 @@ struct MachineState {
} \
type_init(machine_initfn##_register_types)
+extern GlobalProperty hw_compat_4_0[];
+extern const size_t hw_compat_4_0_len;
+
extern GlobalProperty hw_compat_3_1[];
extern const size_t hw_compat_3_1_len;
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index ca65ef18afb4..43df7230a22b 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -293,6 +293,9 @@ int e820_add_entry(uint64_t, uint64_t, uint32_t);
int e820_get_num_entries(void);
bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
+extern GlobalProperty pc_compat_4_0[];
+extern const size_t pc_compat_4_0_len;
+
extern GlobalProperty pc_compat_3_1[];
extern const size_t pc_compat_3_1_len;
On Tue, Jun 04, 2019 at 04:12:24PM -0600, Alex Williamson wrote: > Backport of QEMU v4.1 commit for stable v4.0.1 release > > commit c87759ce876a7a0b17c2bf4f0b964bd51f0ee871 > Author: Alex Williamson <alex.williamson@redhat.com> > Date: Tue May 14 14:14:41 2019 -0600 > > q35: Revert to kernel irqchip > > Commit b2fc91db8447 ("q35: set split kernel irqchip as default") changed > the default for the pc-q35-4.0 machine type to use split irqchip, which > turned out to have disasterous effects on vfio-pci INTx support. KVM > resampling irqfds are registered for handling these interrupts, but > these are non-functional in split irqchip mode. We can't simply test > for split irqchip in QEMU as userspace handling of this interrupt is a > significant performance regression versus KVM handling (GeForce GPUs > assigned to Windows VMs are non-functional without forcing MSI mode or > re-enabling kernel irqchip). > > The resolution is to revert the change in default irqchip mode in the > pc-q35-4.1 machine and create a pc-q35-4.0.1 machine for the 4.0-stable > branch. The qemu-q35-4.0 machine type should not be used in vfio-pci > configurations for devices requiring legacy INTx support without > explicitly modifying the VM configuration to use kernel irqchip. > > Link: https://bugs.launchpad.net/qemu/+bug/1826422 > Fixes: b2fc91db8447 ("q35: set split kernel irqchip as default") > Cc: qemu-stable@nongnu.org > Reviewed-by: Peter Xu <peterx@redhat.com> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> > --- > > Same code as v1, just updating the commit log as a formal backport of > the merged 4.1 commit. > > hw/core/machine.c | 3 +++ > hw/i386/pc.c | 3 +++ > hw/i386/pc_q35.c | 16 ++++++++++++++-- > include/hw/boards.h | 3 +++ > include/hw/i386/pc.h | 3 +++ > 5 files changed, 26 insertions(+), 2 deletions(-) > > diff --git a/hw/core/machine.c b/hw/core/machine.c > index 743fef28982c..5d046a43e3d2 100644 > --- a/hw/core/machine.c > +++ b/hw/core/machine.c > @@ -24,6 +24,9 @@ > #include "hw/pci/pci.h" > #include "hw/mem/nvdimm.h" > > +GlobalProperty hw_compat_4_0[] = {}; > +const size_t hw_compat_4_0_len = G_N_ELEMENTS(hw_compat_4_0); > + > GlobalProperty hw_compat_3_1[] = { > { "pcie-root-port", "x-speed", "2_5" }, > { "pcie-root-port", "x-width", "1" }, > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > index f2c15bf1f2c3..d98b737b8f3b 100644 > --- a/hw/i386/pc.c > +++ b/hw/i386/pc.c > @@ -115,6 +115,9 @@ struct hpet_fw_config hpet_cfg = {.count = UINT8_MAX}; > /* Physical Address of PVH entry point read from kernel ELF NOTE */ > static size_t pvh_start_addr; > > +GlobalProperty pc_compat_4_0[] = {}; > +const size_t pc_compat_4_0_len = G_N_ELEMENTS(pc_compat_4_0); > + > GlobalProperty pc_compat_3_1[] = { > { "intel-iommu", "dma-drain", "off" }, > { "Opteron_G3" "-" TYPE_X86_CPU, "rdtscp", "off" }, > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c > index 372c6b73bebd..45cc29d1adb7 100644 > --- a/hw/i386/pc_q35.c > +++ b/hw/i386/pc_q35.c > @@ -357,7 +357,7 @@ static void pc_q35_machine_options(MachineClass *m) > m->units_per_default_bus = 1; > m->default_machine_opts = "firmware=bios-256k.bin"; > m->default_display = "std"; > - m->default_kernel_irqchip_split = true; > + m->default_kernel_irqchip_split = false; > m->no_floppy = 1; > machine_class_allow_dynamic_sysbus_dev(m, TYPE_AMD_IOMMU_DEVICE); > machine_class_allow_dynamic_sysbus_dev(m, TYPE_INTEL_IOMMU_DEVICE); > @@ -365,12 +365,24 @@ static void pc_q35_machine_options(MachineClass *m) > m->max_cpus = 288; > } > > -static void pc_q35_4_0_machine_options(MachineClass *m) > +static void pc_q35_4_0_1_machine_options(MachineClass *m) > { > pc_q35_machine_options(m); > m->alias = "q35"; > } > > +DEFINE_Q35_MACHINE(v4_0_1, "pc-q35-4.0.1", NULL, > + pc_q35_4_0_1_machine_options); > + > +static void pc_q35_4_0_machine_options(MachineClass *m) > +{ > + pc_q35_4_0_1_machine_options(m); > + m->default_kernel_irqchip_split = true; > + m->alias = NULL; > + compat_props_add(m->compat_props, hw_compat_4_0, hw_compat_4_0_len); > + compat_props_add(m->compat_props, pc_compat_4_0, pc_compat_4_0_len); > +} > + > DEFINE_Q35_MACHINE(v4_0, "pc-q35-4.0", NULL, > pc_q35_4_0_machine_options); > > diff --git a/include/hw/boards.h b/include/hw/boards.h > index e231860666a1..fe1885cbffa0 100644 > --- a/include/hw/boards.h > +++ b/include/hw/boards.h > @@ -293,6 +293,9 @@ struct MachineState { > } \ > type_init(machine_initfn##_register_types) > > +extern GlobalProperty hw_compat_4_0[]; > +extern const size_t hw_compat_4_0_len; > + > extern GlobalProperty hw_compat_3_1[]; > extern const size_t hw_compat_3_1_len; > > diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h > index ca65ef18afb4..43df7230a22b 100644 > --- a/include/hw/i386/pc.h > +++ b/include/hw/i386/pc.h > @@ -293,6 +293,9 @@ int e820_add_entry(uint64_t, uint64_t, uint32_t); > int e820_get_num_entries(void); > bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); > > +extern GlobalProperty pc_compat_4_0[]; > +extern const size_t pc_compat_4_0_len; > + > extern GlobalProperty pc_compat_3_1[]; > extern const size_t pc_compat_3_1_len; >
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