On 20/1/26 19:03, Peter Maydell wrote:
The virt board currently only supports either a GICv2 with a possible
GICv2m for handling MSI interrupts, or else a GICv3 with a possible
ITS for handling MSI interrupts. There is one board property, which
lets you say "its=(off|on)" and controls only whether there is an ITS
or not.
This is awkward for macOS HVF, where you get a GICv3
without ITS and MSI handling needs a GICv2m.
Create a new board property "msi" which gives the user clearer
control over how MSI interrupts are handled:
- msi=its : create an ITS
- msi=gicv2m : create a GICv2m
- msi=off : do not create any MSI handling device
- msi=auto : create the best MSI handling device available
for the GIC version and accelerator
The default is 'auto'.
The existing 'its' property becomes a deprecated property
kept for compatibility. Existing users of "its=on" should
prefer "msi=auto"; users of "its=off" should use "msi=off".
The backwards compatibility cases we need to support are:
(1) TCG, virt-6.1 and earlier: no_tcg_its is set
-- you can have a gicv2 (always with a gicv2m)
-- if you specify gic-version=3 you get a GICv3 without ITS
(2) TCG, virt-6.2 and later:
-- gic-version=2 still has gicv2m
-- gic-version=3 by default gives you an ITS; if you also
say its=off you get GICv3 with no ITS
-- there is no case where we provide a GICv3 and are
unable to provide an ITS for it
(3) KVM (any version):
-- gic-version=2 has a gicv2m
-- gic-version=3 gives you an ITS by default; its=off
will remove it
-- there is no case where we provide a GICv3 and are
unable to provide an ITS for it
(4) HVF:
-- only gic-version=2 works, you get a gicv2m
Thanks for this verbose enumeration. I suppose you started writting
that down before your first line of code :)
Signed-off-by: Peter Maydell <[email protected]>
---
docs/system/arm/virt.rst | 21 ++++++++++++-
hw/arm/virt.c | 64 +++++++++++++++++++++++++++++++++++++++-
include/hw/arm/virt.h | 1 +
3 files changed, 84 insertions(+), 2 deletions(-)
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index b65f571532..471852e4b1 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -3454,7 +3507,13 @@ static void virt_machine_class_init(ObjectClass *oc,
const void *data)
virt_set_its);
object_class_property_set_description(oc, "its",
"Set on/off to enable/disable "
- "ITS instantiation");
+ "ITS instantiation. Deprecated; "
+ "use the msi option instead");
"use the msi= option instead"
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 577b4b3362..53f1dc2199 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -103,6 +103,7 @@ typedef enum VirtMSIControllerType {
VIRT_MSI_CTRL_NONE,
VIRT_MSI_CTRL_GICV2M,
VIRT_MSI_CTRL_ITS,
+ VIRT_MSI_CTRL_NOSEL,
} VirtMSIControllerType;
Pre-existing, no need to expose these, we should restrict to virt.c.
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
