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Re: [Qemu-devel] [PATCH] ioapic: Do not set irr for masked edge IRQs
From: |
Jan Kiszka |
Subject: |
Re: [Qemu-devel] [PATCH] ioapic: Do not set irr for masked edge IRQs |
Date: |
Tue, 26 Apr 2011 15:00:30 +0200 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 |
On 2011-04-09 13:18, Jan Kiszka wrote:
> From: Jan Kiszka <address@hidden>
>
> So far we set IRR for edge IRQs even if the pin is masked. If the guest
> later on unmasks and switches the pin to level-triggered mode, irr will
> remain set, causing an IRQ storm. The point is that setting IRR is not
> correct in this case according to the spec, and avoiding this resolves
> the issue.
>
> Reported-and-tested-by: Isaku Yamahata <address@hidden>
> Signed-off-by: Jan Kiszka <address@hidden>
> ---
> hw/ioapic.c | 5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/hw/ioapic.c b/hw/ioapic.c
> index 569327d..6c26e82 100644
> --- a/hw/ioapic.c
> +++ b/hw/ioapic.c
> @@ -160,8 +160,9 @@ static void ioapic_set_irq(void *opaque, int vector, int
> level)
> s->irr &= ~mask;
> }
> } else {
> - /* edge triggered */
> - if (level) {
> + /* According to the 82093AA manual, we must ignore edge requests
> + * if the input pin is masked. */
> + if (level && !(entry & IOAPIC_LVT_MASKED)) {
> s->irr |= mask;
> ioapic_service(s);
> }
Ping?
Jan
--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux
- Re: [Qemu-devel] [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Aurelien Jarno, 2011/04/03
- Re: [Qemu-devel] [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Isaku Yamahata, 2011/04/03
- Re: [Qemu-devel] [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Isaku Yamahata, 2011/04/03
- [Qemu-devel] Re: [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Jan Kiszka, 2011/04/09
- [Qemu-devel] Re: [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Isaku Yamahata, 2011/04/09
- [Qemu-devel] [PATCH] ioapic: Do not set irr for masked edge IRQs, Jan Kiszka, 2011/04/09
- [Qemu-devel] Re: [PATCH] ioapic: Do not set irr for masked edge IRQs, Jan Kiszka, 2011/04/09
- [Qemu-devel] Re: [PATCH] ioapic: Do not set irr for masked edge IRQs, Jan Kiszka, 2011/04/09
- [Qemu-devel] Re: [PATCH] ioapic: Do not set irr for masked edge IRQs, Isaku Yamahata, 2011/04/09
- Re: [Qemu-devel] [PATCH] ioapic: Do not set irr for masked edge IRQs,
Jan Kiszka <=
- Re: [Qemu-devel] [PATCH] ioapic: Do not set irr for masked edge IRQs, Aurelien Jarno, 2011/04/27
Re: [Qemu-devel] [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Aurelien Jarno, 2011/04/04