From: Jan Beulich <jbeulich@suse.com>
To: Roger Pau Monne <roger.pau@citrix.com>
Cc: xen-devel@lists.xenproject.org,
Andrew Cooper <andrew.cooper3@citrix.com>, Wei Liu <wl@xen.org>,
paul@xen.org
Subject: Re: [PATCH for-4.14 2/8] x86/hvm: don't force vCPU 0 for IRQ 0 when using fixed destination mode
Date: Thu, 18 Jun 2020 15:43:00 +0200 [thread overview]
Message-ID: <ac179f79-3b40-9ff3-9437-16a30e019813@suse.com> (raw)
In-Reply-To: <20200612155640.4101-3-roger.pau@citrix.com>
On 12.06.2020 17:56, Roger Pau Monne wrote:
> When the IO APIC pin mapped to the ISA IRQ 0 has been configured to
> use fixed delivery mode do not forcefully route interrupts to vCPU 0,
> as the OS might have setup those interrupts to be injected to a
> different vCPU, and injecting to vCPU 0 can cause the OS to miss such
> interrupts or errors to happen due to unexpected vectors being
> injected on vCPU 0.
>
> In order to fix remove such handling altogether for fixed destination
> mode pins and just inject them according to the data setup in the
> IO-APIC entry.
>
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Technically
Reviewed-by: Jan Beulich <jbeulich@suse.com>
I wonder though why this was done in the first place - it very much
feels like a workaround for certain guest behavior, and hence
getting rid of it may mean a certain risk of regressions. Not a
very good point in time to make risky changes ...
Jan
next prev parent reply other threads:[~2020-06-18 13:43 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-12 15:56 [PATCH for-4.14 0/8] x86/vpt: fixes for vpt and enable vPIT for PVH dom0 Roger Pau Monne
2020-06-12 15:56 ` [PATCH for-4.14 1/8] x86/hvm: fix vIO-APIC build without IRQ0_SPECIAL_ROUTING Roger Pau Monne
2020-06-15 10:00 ` Paul Durrant
2020-06-15 11:44 ` Roger Pau Monné
2020-06-12 15:56 ` [PATCH for-4.14 2/8] x86/hvm: don't force vCPU 0 for IRQ 0 when using fixed destination mode Roger Pau Monne
2020-06-18 13:43 ` Jan Beulich [this message]
2020-06-18 13:48 ` Roger Pau Monné
2020-06-18 14:08 ` Jan Beulich
2020-06-18 14:18 ` Roger Pau Monné
2020-06-18 14:29 ` Jan Beulich
2020-06-18 14:49 ` Roger Pau Monné
2020-06-18 15:16 ` Jan Beulich
2020-06-12 15:56 ` [PATCH for-4.14 3/8] x86/hvm: fix ISA IRQ 0 handling when set as lowest priority mode in IO APIC Roger Pau Monne
2020-06-18 14:26 ` Jan Beulich
2020-06-18 14:55 ` Roger Pau Monné
2020-06-18 15:20 ` Jan Beulich
2020-06-12 15:56 ` [PATCH for-4.14 4/8] x86/vpt: only try to resume timers belonging to enabled devices Roger Pau Monne
2020-06-18 14:37 ` Jan Beulich
2020-06-18 14:56 ` Roger Pau Monné
2020-06-12 15:56 ` [PATCH for-4.14 5/8] x86/hvm: only translate ISA interrupts to GSIs in virtual timers Roger Pau Monne
2020-06-18 14:47 ` Jan Beulich
2020-06-18 15:03 ` Roger Pau Monné
2020-06-12 15:56 ` [PATCH for-4.14 6/8] x86/vpt: fix injection to remote vCPU Roger Pau Monne
2020-06-18 15:12 ` Jan Beulich
2020-06-18 17:14 ` Roger Pau Monné
2020-06-19 12:37 ` Jan Beulich
2020-06-12 15:56 ` [PATCH for-4.14 7/8] x86/hvm: add hardware domain support to hvm_isa_irq_to_gsi Roger Pau Monne
2020-06-18 15:37 ` Jan Beulich
2020-06-12 15:56 ` [PATCH for-4.14 8/8] x86/hvm: enable emulated PIT for PVH dom0 Roger Pau Monne
2020-06-15 15:33 ` Andrew Cooper
2020-06-15 15:47 ` Roger Pau Monné
2020-06-18 16:05 ` Jan Beulich
2020-06-29 14:46 ` Roger Pau Monné
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