Memory access and ALTP2M are two seperate features, while both depending on
helper xenmem_access_to_p2m_access(). So it betters lives in common p2m.c,
other than mem_access.c which will be compiled out when VM_EVENT=n && ALTP2M=y.
Guard xenmem_access_to_p2m_access() with VM_EVENT || ALTP2M, otherwise it
will become unreachable when both VM_EVENT=n and ALTP2M=n, and hence
violating Misra rule 2.1
We also need to move declaration from mem_access.h to p2m-common.h
An extra blank line is inserted after each case-block to correct coding
style at the same time.
Signed-off-by: Penny Zheng <Penny.Zheng@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
v1 -> v3:
- Guard xenmem_access_to_p2m_access() with VM_EVENT || ALTP2M
- Move declaration from mem_access.h to p2m-common.h
- refine commit message
---
xen/arch/x86/mm/mem_access.c | 36 --------------------------------
xen/arch/x86/mm/p2m.c | 40 ++++++++++++++++++++++++++++++++++++
xen/include/xen/mem_access.h | 5 -----
xen/include/xen/p2m-common.h | 3 +++
4 files changed, 43 insertions(+), 41 deletions(-)
diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
index e6b609064c..e55e53f44c 100644
--- a/xen/arch/x86/mm/mem_access.c
+++ b/xen/arch/x86/mm/mem_access.c
@@ -298,42 +298,6 @@ static int set_mem_access(struct domain *d, struct p2m_domain *p2m,
return rc;
}
-bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
- xenmem_access_t xaccess,
- p2m_access_t *paccess)
-{
- static const p2m_access_t memaccess[] = {
-#define ACCESS(ac) [XENMEM_access_##ac] = p2m_access_##ac
- ACCESS(n),
- ACCESS(r),
- ACCESS(w),
- ACCESS(rw),
- ACCESS(x),
- ACCESS(rx),
- ACCESS(wx),
- ACCESS(rwx),
- ACCESS(rx2rw),
- ACCESS(n2rwx),
- ACCESS(r_pw),
-#undef ACCESS
- };
-
- switch ( xaccess )
- {
- case 0 ... ARRAY_SIZE(memaccess) - 1:
- xaccess = array_index_nospec(xaccess, ARRAY_SIZE(memaccess));
- *paccess = memaccess[xaccess];
- break;
- case XENMEM_access_default:
- *paccess = p2m->default_access;
- break;
- default:
- return false;
- }
-
- return true;
-}
-
/*
* Set access type for a region of gfns.
* If gfn == INVALID_GFN, sets the default access type.
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 759f3273d3..8d34357bcb 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2203,6 +2203,46 @@ void p2m_log_dirty_range(struct domain *d, unsigned long begin_pfn,
guest_flush_tlb_mask(d, d->dirty_cpumask);
}
+#if defined(CONFIG_VM_EVENT) || defined(CONFIG_ALTP2M)
+bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
+ xenmem_access_t xaccess,
+ p2m_access_t *paccess)
+{
+ static const p2m_access_t memaccess[] = {
+#define ACCESS(ac) [XENMEM_access_##ac] = p2m_access_##ac
+ ACCESS(n),
+ ACCESS(r),
+ ACCESS(w),
+ ACCESS(rw),
+ ACCESS(x),
+ ACCESS(rx),
+ ACCESS(wx),
+ ACCESS(rwx),
+ ACCESS(rx2rw),
+ ACCESS(n2rwx),
+ ACCESS(r_pw),
+#undef ACCESS
+ };
+
+ switch ( xaccess )
+ {
+ case 0 ... ARRAY_SIZE(memaccess) - 1:
+ xaccess = array_index_nospec(xaccess, ARRAY_SIZE(memaccess));
+ *paccess = memaccess[xaccess];
+ break;
+
+ case XENMEM_access_default:
+ *paccess = p2m->default_access;
+ break;
+
+ default:
+ return false;
+ }
+
+ return true;
+}
+#endif /* VM_EVENT || ALTP2M */
+
/*
* Local variables:
* mode: C
diff --git a/xen/include/xen/mem_access.h b/xen/include/xen/mem_access.h
index 4de651038d..8e7d9ea2e3 100644
--- a/xen/include/xen/mem_access.h
+++ b/xen/include/xen/mem_access.h
@@ -73,11 +73,6 @@ typedef enum {
/* NOTE: Assumed to be only 4 bits right now on x86. */
} p2m_access_t;
-struct p2m_domain;
-bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
- xenmem_access_t xaccess,
- p2m_access_t *paccess);
-
/*
* Set access type for a region of gfns.
* If gfn == INVALID_GFN, sets the default access type.
diff --git a/xen/include/xen/p2m-common.h b/xen/include/xen/p2m-common.h
index f0bd9a6b98..bd4169caee 100644
--- a/xen/include/xen/p2m-common.h
+++ b/xen/include/xen/p2m-common.h
@@ -43,5 +43,8 @@ int __must_check check_get_page_from_gfn(struct domain *d, gfn_t gfn,
bool readonly, p2m_type_t *p2mt_p,
struct page_info **page_p);
+bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
+ xenmem_access_t xaccess,
+ p2m_access_t *paccess);
#endif /* _XEN_P2M_COMMON_H */
--
2.34.1On 15.01.2026 10:28, Penny Zheng wrote:
> --- a/xen/arch/x86/mm/p2m.c
> +++ b/xen/arch/x86/mm/p2m.c
> @@ -2203,6 +2203,46 @@ void p2m_log_dirty_range(struct domain *d, unsigned long begin_pfn,
> guest_flush_tlb_mask(d, d->dirty_cpumask);
> }
>
> +#if defined(CONFIG_VM_EVENT) || defined(CONFIG_ALTP2M)
> +bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
> + xenmem_access_t xaccess,
> + p2m_access_t *paccess)
> +{
> + static const p2m_access_t memaccess[] = {
> +#define ACCESS(ac) [XENMEM_access_##ac] = p2m_access_##ac
> + ACCESS(n),
> + ACCESS(r),
> + ACCESS(w),
> + ACCESS(rw),
> + ACCESS(x),
> + ACCESS(rx),
> + ACCESS(wx),
> + ACCESS(rwx),
> + ACCESS(rx2rw),
> + ACCESS(n2rwx),
> + ACCESS(r_pw),
> +#undef ACCESS
> + };
> +
> + switch ( xaccess )
> + {
> + case 0 ... ARRAY_SIZE(memaccess) - 1:
> + xaccess = array_index_nospec(xaccess, ARRAY_SIZE(memaccess));
> + *paccess = memaccess[xaccess];
> + break;
> +
> + case XENMEM_access_default:
> + *paccess = p2m->default_access;
> + break;
> +
> + default:
> + return false;
> + }
> +
> + return true;
> +}
> +#endif /* VM_EVENT || ALTP2M */
> +
> /*
> * Local variables:
> * mode: C
> diff --git a/xen/include/xen/mem_access.h b/xen/include/xen/mem_access.h
> index 4de651038d..8e7d9ea2e3 100644
> --- a/xen/include/xen/mem_access.h
> +++ b/xen/include/xen/mem_access.h
> @@ -73,11 +73,6 @@ typedef enum {
> /* NOTE: Assumed to be only 4 bits right now on x86. */
> } p2m_access_t;
>
> -struct p2m_domain;
> -bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
> - xenmem_access_t xaccess,
> - p2m_access_t *paccess);
> -
> /*
> * Set access type for a region of gfns.
> * If gfn == INVALID_GFN, sets the default access type.
> diff --git a/xen/include/xen/p2m-common.h b/xen/include/xen/p2m-common.h
> index f0bd9a6b98..bd4169caee 100644
> --- a/xen/include/xen/p2m-common.h
> +++ b/xen/include/xen/p2m-common.h
> @@ -43,5 +43,8 @@ int __must_check check_get_page_from_gfn(struct domain *d, gfn_t gfn,
> bool readonly, p2m_type_t *p2mt_p,
> struct page_info **page_p);
>
> +bool xenmem_access_to_p2m_access(const struct p2m_domain *p2m,
> + xenmem_access_t xaccess,
> + p2m_access_t *paccess);
CI says "no" on both PPC and RISC-V. I wouldn't be surprised of build issues
on Arm or x86 either, seeing that p2m-common.h doesn't (and shouldn't) include
xen/mem_access.h. It's arch/<arch>/include/asm/p2m.h which is responsible for
the inclusion ahead of including p2m-common.h. Question though is: If this is
an x86-only function, why was its decl put in xen/mem_access.h rather than
x86'es asm/mem_access.h. I'll try that before giving up and handing this back
to you, but may I stress again that you please properly test your changes? It
is not the responsibility of the committer to deal with such fallout.
Jan
On 2026-01-15 04:28, Penny Zheng wrote: > Memory access and ALTP2M are two seperate features, while both depending on > helper xenmem_access_to_p2m_access(). So it betters lives in common p2m.c, > other than mem_access.c which will be compiled out when VM_EVENT=n && ALTP2M=y. > Guard xenmem_access_to_p2m_access() with VM_EVENT || ALTP2M, otherwise it > will become unreachable when both VM_EVENT=n and ALTP2M=n, and hence > violating Misra rule 2.1 > We also need to move declaration from mem_access.h to p2m-common.h > An extra blank line is inserted after each case-block to correct coding > style at the same time. > > Signed-off-by: Penny Zheng <Penny.Zheng@amd.com> > Acked-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
On Thu, Jan 15, 2026 at 10:21 AM Jason Andryuk <jason.andryuk@amd.com> wrote: > On 2026-01-15 04:28, Penny Zheng wrote: > > Memory access and ALTP2M are two seperate features, while both depending > on > > helper xenmem_access_to_p2m_access(). So it betters lives in common > p2m.c, > > other than mem_access.c which will be compiled out when VM_EVENT=n && > ALTP2M=y. > > Guard xenmem_access_to_p2m_access() with VM_EVENT || ALTP2M, otherwise it > > will become unreachable when both VM_EVENT=n and ALTP2M=n, and hence > > violating Misra rule 2.1 > > We also need to move declaration from mem_access.h to p2m-common.h > > An extra blank line is inserted after each case-block to correct coding > > style at the same time. > > > > Signed-off-by: Penny Zheng <Penny.Zheng@amd.com> > > Acked-by: Jan Beulich <jbeulich@suse.com> > > Reviewed-by: Jason Andryuk <jason.andryuk@amd.com> > Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
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