[Xen-changelog] [xen staging] x86/p2m: Drop erroneous #VE-enabled check in ept_set_entry()

[patchbot@xxxxxxx]

commit 448787e16e1457ce4e5f7088140a968fe902adf4
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue Jan 22 18:58:56 2019 +0000
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Tue Jan 29 11:28:11 2019 +0000

    x86/p2m: Drop erroneous #VE-enabled check in ept_set_entry()
    
    Code clearing the "Suppress VE" bit in an EPT entry isn't nececsserily 
running
    in current context.  In ALTP2M_external mode, it definitely is not, and in 
PV
    context, vcpu_altp2m(current) acts upon the HVM union.
    
    Even if we could sensibly resolve the target vCPU, it may legitimately not 
be
    fully set up at this point, so rejecting the EPT modification would be 
buggy.
    
    There is a path in hvm_hap_nested_page_fault() which explicitly emulates #VE
    in the cpu_has_vmx_virt_exceptions case, so the -EOPNOTSUPP part of this
    condition is also wrong.
    
    Drop the !sve check entirely.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
    Release-acked-by: Juergen Gross <jgross@xxxxxxxx>
---
 xen/arch/x86/mm/p2m-ept.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index 2b2bf31aad..bb562607f7 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -702,16 +702,6 @@ ept_set_entry(struct p2m_domain *p2m, gfn_t gfn_, mfn_t 
mfn,
 
     ASSERT(ept);
 
-    if ( !sve )
-    {
-        if ( !cpu_has_vmx_virt_exceptions )
-            return -EOPNOTSUPP;
-
-        /* #VE should be enabled for this vcpu. */
-        if ( gfn_eq(vcpu_altp2m(current).veinfo_gfn, INVALID_GFN) )
-            return -ENXIO;
-    }
-
     /*
      * the caller must make sure:
      * 1. passing valid gfn and mfn at order boundary.
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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