diff mbox series

[v7,14/15] x86: switch to use domheap page for page tables

Message ID 85808fae77da535b2997bede8965d22d5c80c5d3.1590750232.git.hongyxia@amazon.com (mailing list archive)
State Superseded
Headers show
Series switch to domheap for Xen page tables | expand

Commit Message

Hongyan Xia May 29, 2020, 11:11 a.m. UTC 
From: Hongyan Xia <hongyxia@amazon.com>

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Hongyan Xia <hongyxia@amazon.com>
---
 xen/arch/x86/mm.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Comments

Jan Beulich July 15, 2020, 1:16 p.m. UTC | #1 
On 29.05.2020 13:11, Hongyan Xia wrote:
> From: Hongyan Xia <hongyxia@amazon.com>
> 
> Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> Signed-off-by: Hongyan Xia <hongyxia@amazon.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>
with a sufficiently minor remark:

> --- a/xen/arch/x86/mm.c
> +++ b/xen/arch/x86/mm.c
> @@ -4918,10 +4918,11 @@ mfn_t alloc_xen_pagetable_new(void)
>  {
>      if ( system_state != SYS_STATE_early_boot )
>      {
> -        void *ptr = alloc_xenheap_page();
>  
> -        BUG_ON(!hardware_domain && !ptr);
> -        return ptr ? virt_to_mfn(ptr) : INVALID_MFN;
> +        struct page_info *pg = alloc_domheap_page(NULL, 0);
> +
> +        BUG_ON(!hardware_domain && !pg);
> +        return pg ? page_to_mfn(pg) : INVALID_MFN;

pg doesn't even get de-referenced, let alone modified. Hence it
would better be pointer-to-const, despite this possibly feeling a
little odd to some of us given this is a freshly allocated page.

Jan
diff mbox series

Patch

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 38cfa3ce25..16f1aa3344 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4918,10 +4918,11 @@  mfn_t alloc_xen_pagetable_new(void)
 {
     if ( system_state != SYS_STATE_early_boot )
     {
-        void *ptr = alloc_xenheap_page();
 
-        BUG_ON(!hardware_domain && !ptr);
-        return ptr ? virt_to_mfn(ptr) : INVALID_MFN;
+        struct page_info *pg = alloc_domheap_page(NULL, 0);
+
+        BUG_ON(!hardware_domain && !pg);
+        return pg ? page_to_mfn(pg) : INVALID_MFN;
     }
 
     return alloc_boot_pages(1, 1);
@@ -4931,7 +4932,7 @@  mfn_t alloc_xen_pagetable_new(void)
 void free_xen_pagetable_new(mfn_t mfn)
 {
     if ( system_state != SYS_STATE_early_boot && !mfn_eq(mfn, INVALID_MFN) )
-        free_xenheap_page(mfn_to_virt(mfn_x(mfn)));
+        free_domheap_page(mfn_to_page(mfn));
 }
 
 void *alloc_map_clear_xen_pt(mfn_t *pmfn)