Arm will no longer be the only target requiring a commpage,
but it will continue to be the only target placing the page
at the high end of the address space.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/elfload.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 767f54c76d..d34cd4fe43 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -390,11 +390,11 @@ enum {
 
 /* The commpage only exists for 32 bit kernels */
 
-#define ARM_COMMPAGE (intptr_t)0xffff0f00u
+#define HI_COMMPAGE (intptr_t)0xffff0f00u
 
 static bool init_guest_commpage(void)
 {
-    void *want = g2h_untagged(ARM_COMMPAGE & -qemu_host_page_size);
+    void *want = g2h_untagged(HI_COMMPAGE & -qemu_host_page_size);
     void *addr = mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE,
                       MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
 
@@ -2160,8 +2160,8 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
     return sp;
 }
 
-#ifndef ARM_COMMPAGE
-#define ARM_COMMPAGE 0
+#ifndef HI_COMMPAGE
+#define HI_COMMPAGE 0
 #define init_guest_commpage() true
 #endif
 
@@ -2361,7 +2361,7 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr,
     }
 
     loaddr &= -align;
-    if (ARM_COMMPAGE) {
+    if (HI_COMMPAGE) {
         /*
          * Extend the allocation to include the commpage.
          * For a 64-bit host, this is just 4GiB; for a 32-bit host we
@@ -2372,14 +2372,14 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr,
         if (sizeof(uintptr_t) == 8 || loaddr >= 0x80000000u) {
             hiaddr = (uintptr_t) 4 << 30;
         } else {
-            offset = -(ARM_COMMPAGE & -align);
+            offset = -(HI_COMMPAGE & -align);
         }
     }
 
     addr = pgb_find_hole(loaddr, hiaddr - loaddr, align, offset);
     if (addr == -1) {
         /*
-         * If ARM_COMMPAGE, there *might* be a non-consecutive allocation
+         * If HI_COMMPAGE, there *might* be a non-consecutive allocation
          * that can satisfy both.  But as the normal arm32 link base address
          * is ~32k, and we extend down to include the commpage, making the
          * overhead only ~96k, this is unlikely.
@@ -2400,7 +2400,7 @@ static void pgb_dynamic(const char *image_name, long align)
      * All we need is a commpage that satisfies align.
      * If we do not need a commpage, leave guest_base == 0.
      */
-    if (ARM_COMMPAGE) {
+    if (HI_COMMPAGE) {
         uintptr_t addr, commpage;
 
         /* 64-bit hosts should have used reserved_va. */
@@ -2410,7 +2410,7 @@ static void pgb_dynamic(const char *image_name, long align)
          * By putting the commpage at the first hole, that puts guest_base
          * just above that, and maximises the positive guest addresses.
          */
-        commpage = ARM_COMMPAGE & -align;
+        commpage = HI_COMMPAGE & -align;
         addr = pgb_find_hole(commpage, -commpage, align, 0);
         assert(addr != -1);
         guest_base = addr;
-- 
2.25.1

Le 21/12/2021 à 03:50, Richard Henderson a écrit :
> Arm will no longer be the only target requiring a commpage,
> but it will continue to be the only target placing the page
> at the high end of the address space.
> 
> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   linux-user/elfload.c | 18 +++++++++---------
>   1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index 767f54c76d..d34cd4fe43 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -390,11 +390,11 @@ enum {
>   
>   /* The commpage only exists for 32 bit kernels */
>   
> -#define ARM_COMMPAGE (intptr_t)0xffff0f00u
> +#define HI_COMMPAGE (intptr_t)0xffff0f00u
>   
>   static bool init_guest_commpage(void)
>   {
> -    void *want = g2h_untagged(ARM_COMMPAGE & -qemu_host_page_size);
> +    void *want = g2h_untagged(HI_COMMPAGE & -qemu_host_page_size);
>       void *addr = mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE,
>                         MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
>   
> @@ -2160,8 +2160,8 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
>       return sp;
>   }
>   
> -#ifndef ARM_COMMPAGE
> -#define ARM_COMMPAGE 0
> +#ifndef HI_COMMPAGE
> +#define HI_COMMPAGE 0
>   #define init_guest_commpage() true
>   #endif
>   
> @@ -2361,7 +2361,7 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr,
>       }
>   
>       loaddr &= -align;
> -    if (ARM_COMMPAGE) {
> +    if (HI_COMMPAGE) {
>           /*
>            * Extend the allocation to include the commpage.
>            * For a 64-bit host, this is just 4GiB; for a 32-bit host we
> @@ -2372,14 +2372,14 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr,
>           if (sizeof(uintptr_t) == 8 || loaddr >= 0x80000000u) {
>               hiaddr = (uintptr_t) 4 << 30;
>           } else {
> -            offset = -(ARM_COMMPAGE & -align);
> +            offset = -(HI_COMMPAGE & -align);
>           }
>       }
>   
>       addr = pgb_find_hole(loaddr, hiaddr - loaddr, align, offset);
>       if (addr == -1) {
>           /*
> -         * If ARM_COMMPAGE, there *might* be a non-consecutive allocation
> +         * If HI_COMMPAGE, there *might* be a non-consecutive allocation
>            * that can satisfy both.  But as the normal arm32 link base address
>            * is ~32k, and we extend down to include the commpage, making the
>            * overhead only ~96k, this is unlikely.
> @@ -2400,7 +2400,7 @@ static void pgb_dynamic(const char *image_name, long align)
>        * All we need is a commpage that satisfies align.
>        * If we do not need a commpage, leave guest_base == 0.
>        */
> -    if (ARM_COMMPAGE) {
> +    if (HI_COMMPAGE) {
>           uintptr_t addr, commpage;
>   
>           /* 64-bit hosts should have used reserved_va. */
> @@ -2410,7 +2410,7 @@ static void pgb_dynamic(const char *image_name, long align)
>            * By putting the commpage at the first hole, that puts guest_base
>            * just above that, and maximises the positive guest addresses.
>            */
> -        commpage = ARM_COMMPAGE & -align;
> +        commpage = HI_COMMPAGE & -align;
>           addr = pgb_find_hole(commpage, -commpage, align, 0);
>           assert(addr != -1);
>           guest_base = addr;

Applied to my linux-user-for-7.0 branch.

Thanks,
Laurent