Messages in this thread Patch in this message | | | From | alexjlzheng@gmail ... | Subject | [PATCH v2] KVM: x86: Fix poll command | Date | Thu, 13 Apr 2023 20:11:14 +0800 |
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From: Jinliang Zheng <alexjlzheng@tencent.com>
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(): 1. Set Bit 7 when there is an interrupt 2. Return 0 when there is no interrupt
Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com> --- Changes since Version V2: - Keep the logic of pic_poll_read(), only fix the return value --- arch/x86/kvm/i8259.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index 4756bcb5724f..6627f8a52f23 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -411,8 +411,9 @@ 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); + ret |= 0x80; } else { - ret = 0x07; + ret = 0x00; pic_update_irq(s->pics_state); } -- 2.31.1
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