[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: About support for memory event on AMD CPUs
- To: YAN Untitled <yanluyi2010@xxxxxxxxxxx>
- From: Jan Beulich <jbeulich@xxxxxxxx>
- Date: Wed, 24 Nov 2021 08:54:03 +0100
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=V+13BCXAyNHYs2Ox/WODnL1ZpDDuEqkFxsUTr0ND1E8=; b=UfyX8ZIYHC50yVEcRP9QnG//9AbfnR7UzOdULi8YYmPVw+AjfMr8q8vJD3x9S1SF1OC5cZh2WIq+bmUunOcv0P+fbqphQyerBkS/Stji2IvQwiZLxckJKqUD3ipcZd+Pvn4CRzB7Pmc9qB6qofBl3EvHAdYwNdETsS23T3aOh7EAHGZ2sz8iY769vKnKTFDn8QS2wk0aOtNpRFDEVm4t5G/5AYsm3aCdqaKxeIHThslGqYTlQbLEJpFFL1Ts/IpasNM93WMdlFOnoEFNuMObp+LEHhg/TGY2d/SYR1SnRYN3N6hA0zl6gYAl1XFpQuDNWgTL7XLiKRcsl5MhwSSE1A==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=dmpDw1D94v9Jq5nX4M8nsu6kWDso/Gglh2k1ijGfa+rgGMEmxfZNISKv1OBKEf3BjphZx2OX1psPTbNJa3pT11wHDDXiBKErUrHrPekifXuiP4RSRqRCaPR52Yi+mRDelyOuKNyQRSqRweePNILc7ZPEI5NhFuZ4U1UM+qlwE/tYfu3tkk2Ug1f0lQB+y7bPvgTtIHXdv8ISKWk1IIDQ0c2EoFKG1/6sUUSlxzURr/q+eaWSSeygeDIPCHY5LIe5suAVY5mbvQOyKJl0fmb44LyL8gp3KHVZJxGgQDA/pGADxRUxTo0asWZsONmXikO/q7obsH1QQkyl/I0MxhWh9A==
- Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com;
- Cc: "tamas@xxxxxxxxxxxxx" <tamas@xxxxxxxxxxxxx>, "aisaila@xxxxxxxxxxxxxxx" <aisaila@xxxxxxxxxxxxxxx>, "ppircalabu@xxxxxxxxxxxxxxx" <ppircalabu@xxxxxxxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>
- Delivery-date: Wed, 24 Nov 2021 07:54:28 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On 23.11.2021 18:14, YAN Untitled wrote:
> Dear developers,
>
> Short version: is memory event supported on AMD CPUs or is it going to be
> supported?
>
> Long version:
>
> Environment: LibVMI 0.15.0 + Xen 4.14.3 on an **AMD CPU** (5950x), 64-bit
> Debian 11 Dom0.
>
> What I am trying to accomplish: register a **memory event** handler, so that
> I can capture all memory accesses within a specific range issued by any
> thread,
> or all memory accesses within any range issued by a specific thread.
>
> What I got instead: an error from LibVMI saying
> "xc_hvm_set_mem_access failed with code: -1".
>
> Some investigation: by inspecting the source code of LibVMI, I find the direct
> cause is one of the libxc functions, 1) xc_set_mem_access or
> 2) xc_altp2m_set_mem_access, returned error code -1.
>
> After some searching, I found someone else having a similar problem [1]. I
> also
> noted LibVMI says:
>
>> Currently only the Xen Hypervisor provides these features,
>> and some of these are specifically only available on Intel CPUs
>
> However, I can't find the exact confirmation for the availability of memory
> event on AMD CPUs from https://wiki.xenproject.org.
Aiui underlying what you want is altp2m, which presently depends (in
the hypervisor) on EPT being available (and in use for the guest in
question).
Jan
|
