From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <JBeulich@suse.com>,
xen-devel <xen-devel@lists.xenproject.org>
Cc: Paul Durrant <paul.durrant@citrix.com>
Subject: [PATCH v2] x86/HVM: correct hvmemul_map_linear_addr() for multi-page case
Date: Thu, 20 Sep 2018 13:41:26 +0100 [thread overview]
Message-ID: <adf1e4f7-9845-d09c-026d-54cd7a7050cd@citrix.com> (raw)
In-Reply-To: <5B9A381302000078001E81DC@prv1-mh.provo.novell.com>
On 13/09/18 11:12, Jan Beulich wrote:
> The function does two translations in one go for a single guest access.
> Any failure of the first translation step (guest linear -> guest
> physical), resulting in #PF, ought to take precedence over any failure
> of the second step (guest physical -> host physical).
Why? What is the basis of this presumption?
As far as what real hardware does...
This test sets up a ballooned page and a read-only page. I.e. a second
stage fault on the first part of a misaligned access, and a first stage
fault on the second part of the access.
(d1) --- Xen Test Framework ---
(d1) Environment: HVM 64bit (Long mode 4 levels)
(d1) Test splitfault
(d1) About to read
(XEN) *** EPT qual 0000000000000181, gpa 000000000011cffc
(d1) Reading PTR: got 00000000ffffffff
(d1) About to write
(XEN) *** EPT qual 0000000000000182, gpa 000000000011cffc
(d1) ******************************
(d1) PANIC: Unhandled exception at 0008:00000000001047e0
(d1) Vec 14 #PF[-d-sWP] %cr2 000000000011d000
(d1) ******************************
The second stage fault is recognised first, which is contrary to your
presumption, i.e. the code in its current form appears to be correct.
~Andrew
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next prev parent reply other threads:[~2018-09-20 12:41 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-12 9:09 [PATCH] x86/HVM: correct hvmemul_map_linear_addr() for multi-page case Jan Beulich
2018-09-12 11:51 ` Paul Durrant
2018-09-12 12:13 ` Jan Beulich
2018-09-13 10:12 ` [PATCH v2] " Jan Beulich
2018-09-13 11:06 ` Paul Durrant
2018-09-13 11:39 ` Jan Beulich
2018-09-13 11:41 ` Paul Durrant
2018-09-20 12:41 ` Andrew Cooper [this message]
2018-09-20 13:39 ` Jan Beulich
2018-09-20 14:13 ` Andrew Cooper
2018-09-20 14:51 ` Jan Beulich
2018-09-25 12:41 ` Jan Beulich
2018-09-25 15:30 ` Andrew Cooper
2018-09-26 9:27 ` Jan Beulich
2018-10-08 11:53 ` Jan Beulich
2019-07-31 11:26 ` [Xen-devel] " Alexandru Stefan ISAILA
2023-08-30 14:30 ` [Xen-devel] [PATCH] " Roger Pau Monné
2023-08-30 18:09 ` Andrew Cooper
2023-08-31 7:03 ` Jan Beulich
2023-08-31 8:59 ` Roger Pau Monné
2023-08-31 7:14 ` [Xen-devel] " Jan Beulich
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