Hi Juergen,
On 18/08/2023 09:25, Juergen Gross wrote:
On 18.08.23 10:05, Julien Grall wrote:
Hi,
On 18/08/2023 09:00, Juergen Gross wrote:
On 18.08.23 09:39, Julien Grall wrote:
Hi Jan,
On 18/08/2023 07:33, Jan Beulich wrote:
On 17.08.2023 23:43, Julien Grall wrote:
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -339,36 +339,36 @@ typedef uint64_t xen_callback_t;
/* PSR bits (CPSR, SPSR) */
-#define PSR_THUMB (1<<5) /* Thumb Mode enable */
-#define PSR_FIQ_MASK (1<<6) /* Fast Interrupt mask */
-#define PSR_IRQ_MASK (1<<7) /* Interrupt mask */
-#define PSR_ABT_MASK (1<<8) /* Asynchronous Abort mask */
-#define PSR_BIG_ENDIAN (1<<9) /* arm32: Big Endian Mode */
-#define PSR_DBG_MASK (1<<9) /* arm64: Debug Exception
mask */
-#define PSR_IT_MASK (0x0600fc00) /* Thumb If-Then Mask */
-#define PSR_JAZELLE (1<<24) /* Jazelle Mode */
-#define PSR_Z (1<<30) /* Zero condition flag */
+#define PSR_THUMB (1U <<5) /* Thumb Mode enable */
+#define PSR_FIQ_MASK (1U <<6) /* Fast Interrupt mask */
+#define PSR_IRQ_MASK (1U <<7) /* Interrupt mask */
+#define PSR_ABT_MASK (1U <<8) /* Asynchronous Abort mask */
Nit: Did you mean to insert blanks also on the rhs of the <<, like
you ...
+#define PSR_BIG_ENDIAN (1U << 9) /* arm32: Big Endian Mode */
+#define PSR_DBG_MASK (1U << 9) /* arm64: Debug Exception
mask */
+#define PSR_IT_MASK (0x0600fc00U) /* Thumb If-Then Mask */
+#define PSR_JAZELLE (1U << 24) /* Jazelle Mode */
+#define PSR_Z (1U << 30) /* Zero condition flag */
... did everywhere here?
Yes I did. I will update the patch.
As an aside I wonder why they're here: They look like definitions of
processor registers, which aren't under our (Xen's) control.
I agree they are not under Xen's control. However, they are used by
the toolstack and IIRC back then they were not available in any
other headers.
Note that they are only available by the tools and the hypervisor
(see #ifdef above).
I ask in
part because the presence of such constants may then be taken as
justification to add similar things in new ports. Yet such definitions
shouldn't be put here.
From my understanding we are using the public headers to provide
macros/defines that are used by both the toolstack and the
hypervisor. If they are not meant to be exposed to the guest, then
they will be protected with "#if defined(__XEN__) ||
defined(__XEN_TOOLS__)".
I think we are in a similar situation here. So it is not clear where
they should be put if we need to share them between the hypervisor
and the toolstack.
What about include/xen/lib? There are headers below that linked at
build time
via tools/include/Makefile to tools/include/xen/lib.
To me, the question is why would we want to move PSR_* in xen/lib (or
whatever name we decide) but all the other defines that are only used
by the toolstack would still be in public/.
So are you suggesting to move all the tools only information in xen/lib?
I didn't want to suggest that, especially with our general desire to
switch the
tools' interfaces to stable ones.
Ok. If there are a desire to switch the tools interface to stables one.
Then...
I just wanted to point out that there are other locations available already
where such information could be shared between hypervisor and tools.
Especially
information related to hardware (so not an interface we are defining)
might be
a good candidate for such an alternative location.
... I disagree with moving PSR_* outside of the public interface because
they are those defines are used in hypercalls. So they would be part of
the ABI.
Cheers,
--
Julien Grall
