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[xen master] x86/svm: Don't toggle local event delivery on STGI/CLGI



commit 6a6e1e17d662984ab3f5cfb6e84568c810a35fb7
Author:     Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
AuthorDate: Thu May 7 11:55:06 2026 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Wed May 13 16:44:34 2026 +0100

    x86/svm: Don't toggle local event delivery on STGI/CLGI
    
    There is no need to explicitly enable/disable local event delivery on
    STGI/CLGI since HVM event delivery already takes into account the state
    of the GIF (and IF). This ensures the behaviour is consistent regardless
    of whether vGIF is used.
    
    Fold the functions into the callers since they are now only a single
    assignment.
    
    Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/hvm/svm/nestedsvm.c | 26 +++++---------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/xen/arch/x86/hvm/svm/nestedsvm.c b/xen/arch/x86/hvm/svm/nestedsvm.c
index ef6fa5d23b..64fbfe8fa7 100644
--- a/xen/arch/x86/hvm/svm/nestedsvm.c
+++ b/xen/arch/x86/hvm/svm/nestedsvm.c
@@ -19,22 +19,6 @@
 #define NSVM_ERROR_VVMCB        1
 #define NSVM_ERROR_VMENTRY      2
 
-static void
-nestedsvm_vcpu_clgi(struct vcpu *v)
-{
-    /* clear gif flag */
-    vcpu_nestedsvm(v).ns_gif = 0;
-    local_event_delivery_disable(); /* mask events for PV drivers */
-}
-
-static void
-nestedsvm_vcpu_stgi(struct vcpu *v)
-{
-    /* enable gif flag */
-    vcpu_nestedsvm(v).ns_gif = 1;
-    local_event_delivery_enable(); /* unmask events for PV drivers */
-}
-
 int nestedsvm_vmcb_map(struct vcpu *v, uint64_t vmcbaddr)
 {
     struct nestedvcpu *nv = &vcpu_nestedhvm(v);
@@ -161,7 +145,7 @@ int cf_check nsvm_vcpu_reset(struct vcpu *v)
 
     svm->ns_iomap = NULL;
 
-    nestedsvm_vcpu_stgi(v);
+    svm->ns_gif = 1;
     return 0;
 }
 
@@ -667,7 +651,7 @@ nsvm_vcpu_vmentry(struct vcpu *v, struct cpu_user_regs 
*regs,
         return ret;
     }
 
-    nestedsvm_vcpu_stgi(v);
+    svm->ns_gif = 1;
     return 0;
 }
 
@@ -1214,7 +1198,7 @@ nestedsvm_vmexit_defer(struct vcpu *v,
     if ( vmcb->_vintr.fields.vgif_enable )
         vmcb->_vintr.fields.vgif = 0;
     else
-        nestedsvm_vcpu_clgi(v);
+        svm->ns_gif = 0;
 
     svm->ns_vmexit.exitcode = exitcode;
     svm->ns_vmexit.exitinfo1 = exitinfo1;
@@ -1502,7 +1486,7 @@ void svm_vmexit_do_stgi(struct cpu_user_regs *regs, 
struct vcpu *v)
     if ( (inst_len = svm_get_insn_len(v, INSTR_STGI)) == 0 )
         return;
 
-    nestedsvm_vcpu_stgi(v);
+    vcpu_nestedsvm(v).ns_gif = 1;
 
     __update_guest_eip(regs, inst_len);
 }
@@ -1523,7 +1507,7 @@ void svm_vmexit_do_clgi(struct cpu_user_regs *regs, 
struct vcpu *v)
     if ( (inst_len = svm_get_insn_len(v, INSTR_CLGI)) == 0 )
         return;
 
-    nestedsvm_vcpu_clgi(v);
+    vcpu_nestedsvm(v).ns_gif = 0;
 
     /* After a CLGI no interrupts should come */
     intr = vmcb_get_vintr(vmcb);
--
generated by git-patchbot for /home/xen/git/xen.git#master



 


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