From a3019170b2a371075cde819089763c4fdefaf69a Mon Sep 17 00:00:00 2001 From: Feng Wu Date: Thu, 10 Dec 2015 13:12:06 +0100 Subject: [PATCH] vmx: suppress posting interrupts when 'SN' is set Currently, we don't support urgent interrupt, all interrupts are recognized as non-urgent interrupt, so we cannot send posted-interrupt when 'SN' is set. Signed-off-by: Feng Wu Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Jan Beulich Acked-by: --- xen/arch/x86/hvm/vmx/vmx.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index f7c5e4f9dc..bc7d370e68 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -1726,8 +1726,35 @@ static void vmx_deliver_posted_intr(struct vcpu *v, u8 vector) */ pi_set_on(&v->arch.hvm_vmx.pi_desc); } - else if ( !pi_test_and_set_on(&v->arch.hvm_vmx.pi_desc) ) + else { + struct pi_desc old, new, prev; + + prev.control = v->arch.hvm_vmx.pi_desc.control; + + do { + /* + * Currently, we don't support urgent interrupt, all + * interrupts are recognized as non-urgent interrupt, + * Besides that, if 'ON' is already set, no need to + * sent posted-interrupts notification event as well, + * according to hardware behavior. + */ + if ( pi_test_sn(&prev) || pi_test_on(&prev) ) + { + vcpu_kick(v); + return; + } + + old.control = v->arch.hvm_vmx.pi_desc.control & + ~((1 << POSTED_INTR_ON) | (1 << POSTED_INTR_SN)); + new.control = v->arch.hvm_vmx.pi_desc.control | + (1 << POSTED_INTR_ON); + + prev.control = cmpxchg(&v->arch.hvm_vmx.pi_desc.control, + old.control, new.control); + } while ( prev.control != old.control ); + __vmx_deliver_posted_interrupt(v); return; } -- 2.39.5