On 24.09.20 19:02, Oleksandr wrote:
Hi
On 24.09.20 14:08, Jan Beulich wrote:
Hi Jan
On 23.09.2020 22:16, Oleksandr wrote:
On 23.09.20 21:03, Julien Grall wrote:
On 10/09/2020 21:22, Oleksandr Tyshchenko wrote:
From: Oleksandr Tyshchenko <oleksandr_tyshche...@epam.com>
@@ -91,6 +108,28 @@ struct arch_domain
#endif
} __cacheline_aligned;
+enum hvm_io_completion {
+ HVMIO_no_completion,
+ HVMIO_mmio_completion,
+ HVMIO_pio_completion
+};
+
+struct hvm_vcpu_io {
+ /* I/O request in flight to device model. */
+ enum hvm_io_completion io_completion;
+ ioreq_t io_req;
+
+ /*
+ * HVM emulation:
+ * Linear address @mmio_gla maps to MMIO physical frame
@mmio_gpfn.
+ * The latter is known to be an MMIO frame (not RAM).
+ * This translation is only valid for accesses as per
@mmio_access.
+ */
+ struct npfec mmio_access;
+ unsigned long mmio_gla;
+ unsigned long mmio_gpfn;
+};
+
Why do we need to re-define most of this? Can't this just be in common
code?
Jan asked almost the similar question in "[PATCH V1 02/16] xen/ioreq:
Make x86's IOREQ feature common".
Please see my answer there:
https://patchwork.kernel.org/patch/11769105/#23637511
Theoretically we could move this to the common code, but the
question is
how to be with other struct fields the x86's struct hvm_vcpu_io
has/needs but
Arm's seems not, would it be possible to logically split struct
hvm_vcpu_io into common and arch parts?
Have struct vcpu_io and struct arch_vcpu_io as a sub-part of it?
Although it is going to pull a lot of changes into x86/hvm/*, yes this
way
we indeed could logically split struct hvm_vcpu_io into common and
arch parts in a clear way.
If it is really worth it, I will start looking into it.
Julien, I noticed that three fields mmio* are not used within current
series on Arm. Do we expect them to be used later on?
I would rather not add fields which are not used. We could add them when
needed.
Would be the following acceptable?
1. Both fields "io_completion" and "io_req" (which seems to be the only
fields used in common/ioreq.c) are moved to common struct vcpu as part
of struct vcpu_io,
enum hvm_io_completion is also moved (and renamed).
2. We remove everything related to hvm_vcpu* from the Arm header.
3. x86's struct hvm_vcpu_io stays as it is (but without two fields
"io_completion" and "io_req").
I think, this way we separate a common part and reduce Xen changes
(which are getting bigger).
--
Regards,
Oleksandr Tyshchenko
