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From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Rian Quinn <rianquinn@gmail.com>
Cc: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	"Johnson, Ethan" <ejohns48@cs.rochester.edu>
Subject: Re: [Xen-devel] More questions about Xen memory layout/usage, access to guest memory
Date: Thu, 22 Aug 2019 23:42:06 +0100	[thread overview]
Message-ID: <7b56ce05-3cd8-4133-efcb-608a951d0843@citrix.com> (raw)
In-Reply-To: <CANmpu8U3W1+Jh6KiQTndZRSd5Nw081E2FcYig1Jx3tpT5gxrow@mail.gmail.com>

On 22/08/2019 16:06, Rian Quinn wrote:
> I can at least confirm that no emulation is needed to execute a Linux
> guest, even with the Xen PVH interface, but I don't think that works
> out of the box today with Xen, something we are currently working on
> and will hopefully have some more data near the end of the year.
> x2APIC helps, but it takes some work to convince Linux to use that
> currently. The trick is to avoid PortIO and, where possible, MMIO
> interfaces.

There is a bit in the CPUID leaves which allegedly should cause Linux to
try and use x2apic, but I can easily see this having bitrotted.

It is certainly something we need to fix.

~Andrew

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  reply	other threads:[~2019-08-22 22:42 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-16 19:51 [Xen-devel] More questions about Xen memory layout/usage, access to guest memory Johnson, Ethan
2019-08-17 11:04 ` Andrew Cooper
2019-08-22  2:06   ` Johnson, Ethan
2019-08-22 13:51     ` Andrew Cooper
2019-08-22 15:06       ` Rian Quinn
2019-08-22 22:42         ` Andrew Cooper [this message]
2019-08-22 17:36       ` Tamas K Lengyel
2019-08-22 22:49         ` Andrew Cooper
2019-08-22 20:57       ` Rich Persaud
2019-08-22 22:39         ` Andrew Cooper
2019-08-22 23:06           ` Tamas K Lengyel
2019-08-23  0:03             ` Andrew Cooper
2019-08-23  1:12               ` Tamas K Lengyel

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