From: Anchal Agarwal <anchalag@amazon.com>
To: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>,
<hpa@zytor.com>, <x86@kernel.org>, <jgross@suse.com>,
<linux-pm@vger.kernel.org>, <linux-mm@kvack.org>,
<kamatam@amazon.com>, <sstabellini@kernel.org>,
<konrad.wilk@oracle.com>, <roger.pau@citrix.com>,
<axboe@kernel.dk>, <davem@davemloft.net>, <rjw@rjwysocki.net>,
<len.brown@intel.com>, <pavel@ucw.cz>, <peterz@infradead.org>,
<eduval@amazon.com>, <sblbir@amazon.com>,
<xen-devel@lists.xenproject.org>, <vkuznets@redhat.com>,
<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<dwmw@amazon.co.uk>, <benh@kernel.crashing.org>
Subject: Re: [PATCH 03/12] x86/xen: Introduce new function to map HYPERVISOR_shared_info on Resume
Date: Thu, 4 Jun 2020 23:03:07 +0000 [thread overview]
Message-ID: <20200604230307.GB25251@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> (raw)
In-Reply-To: <72989b50-0c13-7a2b-19e2-de4a3646c83f@oracle.com>
On Sat, May 30, 2020 at 07:02:01PM -0400, Boris Ostrovsky wrote:
> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
>
>
>
> On 5/19/20 7:25 PM, Anchal Agarwal wrote:
> > Introduce a small function which re-uses shared page's PA allocated
> > during guest initialization time in reserve_shared_info() and not
> > allocate new page during resume flow.
> > It also does the mapping of shared_info_page by calling
> > xen_hvm_init_shared_info() to use the function.
> >
> > Signed-off-by: Anchal Agarwal <anchalag@amazon.com>
> > ---
> > arch/x86/xen/enlighten_hvm.c | 7 +++++++
> > arch/x86/xen/xen-ops.h | 1 +
> > 2 files changed, 8 insertions(+)
> >
> > diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
> > index e138f7de52d2..75b1ec7a0fcd 100644
> > --- a/arch/x86/xen/enlighten_hvm.c
> > +++ b/arch/x86/xen/enlighten_hvm.c
> > @@ -27,6 +27,13 @@
> >
> > static unsigned long shared_info_pfn;
> >
> > +void xen_hvm_map_shared_info(void)
> > +{
> > + xen_hvm_init_shared_info();
> > + if (shared_info_pfn)
> > + HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn));
> > +}
> > +
>
>
> AFAICT it is only called once so I don't see a need for new routine.
>
>
HYPERVISOR_shared_info can only be mapped in this scope without refactoring
much of the code.
> And is it possible for shared_info_pfn to be NULL in resume path (which
> is where this is called)?
>
>
I don't think it should be, still a sanity check but I don't think its needed there
because hibernation will fail in any case if thats the case.
However, HYPERVISOR_shared_info does needs to be re-mapped on resume as its been
marked to dummy address on suspend. Its also safe in case va changes.
Does the answer your question?
> -boris
-Anchal
>
>
next prev parent reply other threads:[~2020-06-04 23:03 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 23:24 [PATCH 00/12] Fix PM hibernation in Xen guests Anchal Agarwal
2020-05-19 23:24 ` [PATCH 01/12] xen/manage: keep track of the on-going suspend mode Anchal Agarwal
2020-05-30 22:26 ` Boris Ostrovsky
2020-06-01 21:00 ` Agarwal, Anchal
2020-06-01 22:39 ` Boris Ostrovsky
2020-05-19 23:25 ` [PATCH 02/12] xenbus: add freeze/thaw/restore callbacks support Anchal Agarwal
2020-05-30 22:56 ` Boris Ostrovsky
2020-06-01 23:36 ` Agarwal, Anchal
2020-05-19 23:25 ` [PATCH 03/12] x86/xen: Introduce new function to map HYPERVISOR_shared_info on Resume Anchal Agarwal
2020-05-30 23:02 ` Boris Ostrovsky
2020-06-04 23:03 ` Anchal Agarwal [this message]
2020-06-05 21:39 ` Boris Ostrovsky
2020-06-08 16:52 ` Anchal Agarwal
2020-06-08 18:49 ` Boris Ostrovsky
2020-05-19 23:26 ` [PATCH 04/12] x86/xen: add system core suspend and resume callbacks Anchal Agarwal
2020-05-30 23:10 ` Boris Ostrovsky
2020-06-03 22:40 ` Agarwal, Anchal
2020-06-05 21:24 ` Boris Ostrovsky
2020-06-08 17:09 ` Anchal Agarwal
2020-05-19 23:26 ` [PATCH 05/12] genirq: Shutdown irq chips in suspend/resume during hibernation Anchal Agarwal
2020-05-19 23:29 ` Singh, Balbir
2020-05-19 23:36 ` Agarwal, Anchal
2020-05-19 23:34 ` Anchal Agarwal
2020-05-30 23:17 ` Boris Ostrovsky
2020-06-01 20:46 ` Agarwal, Anchal
2020-05-19 23:27 ` [PATCH 06/12] xen-blkfront: add callbacks for PM suspend and hibernation Anchal Agarwal
2020-05-20 5:00 ` kbuild test robot
2020-05-20 5:07 ` kbuild test robot
2020-05-21 23:48 ` Anchal Agarwal
2020-05-22 1:43 ` Singh, Balbir
2020-05-28 12:30 ` Roger Pau Monné
2020-05-19 23:28 ` [PATCH 07/12] xen-netfront: " Anchal Agarwal
2020-05-19 23:28 ` [PATCH 08/12] xen/time: introduce xen_{save,restore}_steal_clock Anchal Agarwal
2020-05-30 23:32 ` Boris Ostrovsky
2020-05-19 23:28 ` [PATCH 09/12] x86/xen: save and restore steal clock Anchal Agarwal
2020-05-30 23:44 ` Boris Ostrovsky
2020-06-04 18:33 ` Anchal Agarwal
2020-05-19 23:29 ` [PATCH 10/12] xen: Introduce wrapper for save/restore sched clock offset Anchal Agarwal
2020-05-19 23:29 ` [PATCH 11/12] xen: Update sched clock offset to avoid system instability in hibernation Anchal Agarwal
2020-05-19 23:29 ` [PATCH 12/12] PM / hibernate: update the resume offset on SNAPSHOT_SET_SWAP_AREA Anchal Agarwal
2020-05-28 17:59 ` [PATCH 00/12] Fix PM hibernation in Xen guests Agarwal, Anchal
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