[xen master] x86/hvm: make X86_EMU_USE_PIRQ optional

[patchbot@xxxxxxx]

commit 72cad62abbaab656acee0835099b0260ac6f13ab
Author:     Roger Pau Monne <roger.pau@xxxxxxxxxx>
AuthorDate: Thu Jan 25 10:30:40 2024 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Thu Jan 25 17:46:57 2024 +0000

    x86/hvm: make X86_EMU_USE_PIRQ optional
    
    Allow selecting X86_EMU_USE_PIRQ for HVM guests, so it's no longer mandated 
to
    be always on.
    
    There's no restriction in Xen that forces such feature to be always on for 
HVM
    guests, as for example PVH guests don't support it, as such allow toolstack 
to
    select whether to enabled it on a per-domain basis.
    
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/domain.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 8a31d18f69..bda853e3c9 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -725,7 +725,9 @@ static bool emulation_flags_ok(const struct domain *d, 
uint32_t emflags)
              emflags != (X86_EMU_VPCI | X86_EMU_LAPIC | X86_EMU_IOAPIC) )
             return false;
         if ( !is_hardware_domain(d) &&
-             emflags != (X86_EMU_ALL & ~X86_EMU_VPCI) &&
+             /* HVM PIRQ feature is user-selectable. */
+             (emflags & ~X86_EMU_USE_PIRQ) !=
+             (X86_EMU_ALL & ~(X86_EMU_VPCI | X86_EMU_USE_PIRQ)) &&
              emflags != X86_EMU_LAPIC )
             return false;
     }
--
generated by git-patchbot for /home/xen/git/xen.git#master