From fc57ac2c9ca8109ea97fcc594f4be436944230cc Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 14 May 2014 17:40:58 +0200 Subject: [PATCH] KVM: lapic: sync highest ISR to hardware apic on EOI When Hyper-V enlightenments are in effect, Windows prefers to issue an Hyper-V MSR write to issue an EOI rather than an x2apic MSR write. The Hyper-V MSR write is not handled by the processor, and besides being slower, this also causes bugs with APIC virtualization. The reason is that on EOI the processor will modify the highest in-service interrupt (SVI) field of the VMCS, as explained in section 29.1.4 of the SDM; every other step in EOI virtualization is already done by apic_send_eoi or on VM entry, but this one is missing. We need to do the same, and be careful not to muck with the isr_count and highest_isr_cache fields that are unused when virtual interrupt delivery is enabled. Cc: stable@vger.kernel.org Reviewed-by: Yang Zhang Signed-off-by: Paolo Bonzini --- Reading git-format-patch failed