On 6/5/2023 12:50 PM, Alex Elder wrote:
On 5/9/23 3:47 PM, Elliot Berman wrote:
Enable support for creating irqfds which can raise an interrupt on a
Gunyah virtual machine. irqfds are exposed to userspace as a Gunyah VM
function with the name "irqfd". If the VM devicetree is not configured
to create a doorbell with the corresponding label, userspace will still
be able to assert the eventfd but no interrupt will be raised on the
guest.
Co-developed-by: Prakruthi Deepak Heragu <quic_pheragu@xxxxxxxxxxx>
Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@xxxxxxxxxxx>
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
I have a minor suggestion. I think I'd like to look at this
again, so:
Acked-by: Alex Elder <elder@xxxxxxxxxx>
---
Documentation/virt/gunyah/vm-manager.rst | 2 +-
drivers/virt/gunyah/Kconfig | 9 ++
drivers/virt/gunyah/Makefile | 1 +
drivers/virt/gunyah/gunyah_irqfd.c | 180 +++++++++++++++++++++++
include/uapi/linux/gunyah.h | 35 +++++
5 files changed, 226 insertions(+), 1 deletion(-)
create mode 100644 drivers/virt/gunyah/gunyah_irqfd.c
. . .
@@ -99,6 +102,38 @@ struct gh_fn_vcpu_arg {
__u32 id;
};
+/**
+ * enum gh_irqfd_flags - flags for use in gh_fn_irqfd_arg
+ * @GH_IRQFD_FLAGS_LEVEL: make the interrupt operate like a level
triggered
+ * interrupt on guest side. Triggering IRQFD
before
+ * guest handles the interrupt causes
interrupt to
+ * stay asserted.
+ */
+enum gh_irqfd_flags {
+ GH_IRQFD_FLAGS_LEVEL = 1UL << 0,
BIT(0), /* ? */
The BIT macro isn't a standard C macro and isn't defined by Linux, so it
causes compile errors at least for me when I use it in userspace.
+};
+
+/**
+ * struct gh_fn_irqfd_arg - Arguments to create an irqfd function.
+ *
+ * Create this function with &GH_VM_ADD_FUNCTION using type
&GH_FN_IRQFD.
+ *
+ * Allows setting an eventfd to directly trigger a guest interrupt.
+ * irqfd.fd specifies the file descriptor to use as the eventfd.
+ * irqfd.label corresponds to the doorbell label used in the guest
VM's devicetree.
+ *
+ * @fd: an eventfd which when written to will raise a doorbell
+ * @label: Label of the doorbell created on the guest VM
+ * @flags: see &enum gh_irqfd_flags
+ * @padding: padding bytes
+ */
+struct gh_fn_irqfd_arg {
+ __u32 fd;
+ __u32 label;
+ __u32 flags;
+ __u32 padding;
+};
+
/**
* struct gh_fn_desc - Arguments to create a VM function
* @type: Type of the function. See &enum gh_fn_type.
