Mailing List Archive

commit eb47953c55e4ace50de233d12e2a9a7f93423f20
Author: Jan Beulich <jbeulich@suse.com>
AuthorDate: Mon Jan 9 14:25:29 2023 +0100
Commit: Jan Beulich <jbeulich@suse.com>
CommitDate: Mon Jan 9 14:25:29 2023 +0100

x86/shadow: move bogus HVM checks in sh_pagetable_dying()

Perhaps these should have been dropped right in 2fb2dee1ac62 ("x86/mm:
pagetable_dying() is HVM-only"). Convert both to assertions, noting that
in particular the one in the 3-level variant of the function came too
late anyway - first thing there we access the HVM part of a union.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
xen/arch/x86/mm/shadow/multi.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index e9e80cbaeb..5595f42162 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -3777,6 +3777,8 @@ static void cf_check sh_pagetable_dying(paddr_t gpa)
unsigned long l3gfn;
mfn_t l3mfn;

+ ASSERT(is_hvm_domain(d));
+
gcr3 = v->arch.hvm.guest_cr[3];
/* fast path: the pagetable belongs to the current context */
if ( gcr3 == gpa )
@@ -3819,7 +3821,7 @@ static void cf_check sh_pagetable_dying(paddr_t gpa)
: shadow_hash_lookup(d, mfn_x(gmfn), SH_type_l2_pae_shadow);
}

- if ( mfn_valid(smfn) && is_hvm_domain(d) )
+ if ( mfn_valid(smfn) )
{
gmfn = _mfn(mfn_to_page(smfn)->v.sh.back);
mfn_to_page(gmfn)->pagetable_dying = true;
@@ -3851,6 +3853,8 @@ static void cf_check sh_pagetable_dying(paddr_t gpa)
mfn_t smfn, gmfn;
p2m_type_t p2mt;

+ ASSERT(is_hvm_domain(d));
+
gmfn = get_gfn_query(d, _gfn(gpa >> PAGE_SHIFT), &p2mt);
paging_lock(d);

@@ -3860,7 +3864,7 @@ static void cf_check sh_pagetable_dying(paddr_t gpa)
smfn = shadow_hash_lookup(d, mfn_x(gmfn), SH_type_l4_64_shadow);
#endif

- if ( mfn_valid(smfn) && is_hvm_domain(d) )
+ if ( mfn_valid(smfn) )
{
mfn_to_page(gmfn)->pagetable_dying = true;
shadow_unhook_mappings(d, smfn, 1/* user pages only */);
--
generated by git-patchbot for /home/xen/git/xen.git#master