[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH V4 14/24] arm/ioreq: Introduce arch specific bits for IOREQ/DM features

On 20.01.21 17:50, Julien Grall wrote:
Hi Oleksandr,

Hi Julien

On 17/01/2021 18:52, Oleksandr wrote:
  diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 6819a3b..c235e5b 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -10,6 +10,7 @@
  #include <asm/gic.h>
  #include <asm/vgic.h>
  #include <asm/vpl011.h>
+#include <public/hvm/dm_op.h>

May I ask, why do you need to include dm_op.h here?
I needed to include that header to make some bits visible (XEN_DMOP_IO_RANGE_PCI, struct xen_dm_op_buf, etc). Why here - is a really good question. I don't remember exactly, probably I followed x86's domain.h which also included it. So, trying to remove the inclusion here, I get several build failures on Arm which could be fixed if I include that header from dm.h and ioreq.h:

Shall I do this way?

If the failure are indeded because ioreq.h and dm.h use definition from public/hvm/dm_op.h, then yes. Can you post the errors?
Please see attached, although I built for Arm32 (and the whole series), I think errors are valid for Arm64 also.


error1.txt - when remove #include <public/hvm/dm_op.h> from asm-arm/domain.h

For this one, I agree that including <public/hvm/dm_op.h> in xen.h looks the best solution.

Yes, I assume you meant in "ioreq.h"

error2.txt - when add #include <public/hvm/dm_op.h> to xen/ioreq.h

It looks like the error is happening in dm.c rather than xen/dm.h. Any reason to not include <public/hvm/dm_op.h> in dm.c directly?
Including it directly doesn't solve build issue.
If I am not mistaken in order to follow requirements how to include headers (alphabetic order, public* should be included after xen* and asm* ones, etc) the dm.h gets included the first in dm.c, and dm_op.h gets included the last. We can avoid build issue if we change inclusion order a bit, what I mean is to include dm.h after hypercall.h at least (because hypercall.h already includes dm_op.h). But this breaks the requirements and is not way to go.
Now I am in doubt how to overcome this.

error3.txt - when add #include <public/hvm/dm_op.h> to xen/dm.h

I am a bit confused with this one. Isn't it the same as error1.txt?

The same, please ignore them, sorry for the confusion.


  #include <public/hvm/params.h>
    struct hvm_domain
@@ -262,6 +263,8 @@ static inline void arch_vcpu_block(struct vcpu *v) {}     #define arch_vm_assist_valid_mask(d) (1UL << VMASST_TYPE_runstate_update_flag)
  +#define has_vpci(d)    ({ (void)(d); false; })
  #endif /* __ASM_DOMAIN_H__ */
diff --git a/xen/include/asm-arm/hvm/ioreq.h b/xen/include/asm-arm/hvm/ioreq.h
new file mode 100644
index 0000000..19e1247
--- /dev/null
+++ b/xen/include/asm-arm/hvm/ioreq.h

Shouldn't this directly be under asm-arm/ rather than asm-arm/hvm/ as the IOREQ is now meant to be agnostic?
Good question... The _common_ IOREQ code is indeed arch-agnostic. But, can the _arch_ IOREQ code be treated as really subarch-agnostic? I think, on Arm it can and it is most likely ok to keep it in "asm-arm/", but how it would be correlated with x86's IOREQ code which is HVM specific and located
in "hvm" subdir?

Sorry, I don't understand your answer/questions. So let me ask the question differently, is asm-arm/hvm/ioreq.h going to be included from common code?

Sorry if I was unclear.

If the answer is no, then I see no reason to follow the x86 here.
If the answer is yes, then I am quite confused why half of the series tried to remove "hvm" from the function name but we still include "asm/hvm/ioreq.h".

Answer is yes. Even if we could to avoid including that header from the common code somehow, we would still have #include <public/hvm/*>, is_hvm_domain().

I saw Jan answered about this one. Let me know if you need more input.

Thank you, I think, no. Everything is clear at the moment.



Oleksandr Tyshchenko



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.