From: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx> According to the hardware manual, when the Poll command is issued, the byte returned by the I/O read is 1 in Bit 7 when there is an interrupt, and the highest priority binary code in Bits 2:0. The current pic simulation code is not implemented strictly according to the above expression. Fix the implementation of pic_poll_read(), set Bit 7 when there is an interrupt. Signed-off-by: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx> --- arch/x86/kvm/i8259.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index 4756bcb5724f..861872e2641a 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -411,6 +411,8 @@ static u32 pic_poll_read(struct kvm_kpic_state *s, u32 addr1) pic_clear_isr(s, ret); if (addr1 >> 7 || ret != 2) pic_update_irq(s->pics_state); + /* Bit 7 is 1, means there's an interrupt */ + ret |= 0x80; } else { ret = 0x07; pic_update_irq(s->pics_state); -- 2.31.1