On 08.12.25 14:44, Jan Beulich wrote:
On 28.11.2025 16:22, Grygorii Strashko wrote:
--- a/xen/arch/x86/include/asm/mm.h
+++ b/xen/arch/x86/include/asm/mm.h
@@ -619,9 +619,12 @@ void __iomem *ioremap_wc(paddr_t pa, size_t len);
extern int memory_add(unsigned long spfn, unsigned long epfn, unsigned int pxm);
-void domain_set_alloc_bitsize(struct domain *d);
-unsigned int domain_clamp_alloc_bitsize(struct domain *d, unsigned int bits);
-#define domain_clamp_alloc_bitsize(d, bits) domain_clamp_alloc_bitsize(d, bits)
+#ifdef CONFIG_PV32
+#define domain_clamp_alloc_bitsize(d, bits)
\
+ (((d) && (d)->arch.pv.physaddr_bitsize)
\
+ ? min_t(uint32_t, (d)->arch.pv.physaddr_bitsize, (bits))
\
+ : (bits))
I'm not quite sure if converting to a macro was a good idea. But now that it's
done this way, so be it. Just that a couple of issues may want / need sorting:
- d is now evaluated up to 3 times,
- indentation is wrong,
- the use of uint32_t is against ./CODING_STYLE (I dislike the use of min_t()
anyway, but what do you do when a macro was asked for; of course we could
[easily] arrange for BITS_PER_LONG to be of type "unsigned int"),
- the use of "bits" in min_t() doesn't really need parentheses.
I'll update it.
--- a/xen/arch/x86/pv/domain.c
+++ b/xen/arch/x86/pv/domain.c
@@ -254,7 +254,11 @@ int switch_compat(struct domain *d)
goto undo_and_fail;
}
- domain_set_alloc_bitsize(d);
+ if ( MACH2PHYS_COMPAT_NR_ENTRIES(d) < max_page )
You mention the change in condition in the revlog (but not in the description),
The updated chunk was based on snippet from Andrew [1], which
used incorrect condition - I've changed it and noted in change log
[1] https://patchwork.kernel.org/comment/26680551/
and I'm having trouble to follow why ...
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -1119,26 +1119,6 @@ unmap:
return ret;
}
-void domain_set_alloc_bitsize(struct domain *d)
-{
The domain_set_alloc_bitsize() inlined in switch_compat() and x86 PV domain
always created as 64bit domain.
At the beginning of switch_compat() there is:
( is_pv_32bit_domain(d) )
return 0;
[2]
above ensures that switch_compat() can be actually called only once (at least
it can reach
point [2] only once, because there is no way to reset PV domain state
32bit->64bit
this is original condition which says:
- if ( !is_pv_32bit_domain(d) ||
do nothing if !is_pv_32bit_domain(d)
- for inlined code is_pv_32bit_domain(d) == true, so is_pv_32bit_domain(d) can
be ignored
- (MACH2PHYS_COMPAT_NR_ENTRIES(d) >= max_page) ||
do nothing if (MACH2PHYS_COMPAT_NR_ENTRIES(d) >= max_page)
- inlinded code should proceed if this condition is opposite
(MACH2PHYS_COMPAT_NR_ENTRIES(d) < max_page)
- d->arch.physaddr_bitsize > 0 )
do nothing if d->arch.physaddr_bitsize > 0 (already set)
- inlined code will be executed only once, so (d->arch.physaddr_bitsize ==/!=
0)
can be ignored
... this 3rd part is going away.
Another observation: MACH2PHYS_COMPAT_NR_ENTRIES(d) is looks like a const, as
(d)->arch.hv_compat_vstart is always 0.
grep -rw hv_compat_vstart ./*
./arch/x86/include/asm/config.h:#define HYPERVISOR_COMPAT_VIRT_START(d)
((d)->arch.hv_compat_vstart)
./arch/x86/include/asm/domain.h: unsigned int hv_compat_vstart;
--
Best regards,
-grygorii
