From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Date: Wed, 02 Oct 2019 12:40:02 +0000 Subject: Re: [PATHC v6] video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver Message-Id: <20191002124002.GL17454@sasha-vm> List-Id: References: <20190918060227.6834-1-weh@microsoft.com> <20191001184828.GF8171@sasha-vm> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dexuan Cui Cc: Michael Kelley , Wei Hu , "rdunlap@infradead.org" , "shc_work@mail.ru" , "gregkh@linuxfoundation.org" , "lee.jones@linaro.org" , "alexandre.belloni@bootlin.com" , "baijiaju1990@gmail.com" , "info@metux.net" , "linux-hyperv@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "linux-fbdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Stephen Hemminger , Haiyang Zhang , KY Srinivasan On Wed, Oct 02, 2019 at 08:09:41AM +0000, Dexuan Cui wrote: >> -----Original Message----- >> From: Sasha Levin >> Sent: Tuesday, October 1, 2019 11:48 AM >> >> On Fri, Sep 20, 2019 at 05:26:34PM +0000, Michael Kelley wrote: >> >From: Michael Kelley Sent: Wednesday, >> September 18, 2019 2:48 PM >> >> > >> >> > Without deferred IO support, hyperv_fb driver informs the host to refresh >> >> > the entire guest frame buffer at fixed rate, e.g. at 20Hz, no matter there >> >> > is screen update or not. This patch supports deferred IO for screens in >> >> > graphics mode and also enables the frame buffer on-demand refresh. The >> >> > highest refresh rate is still set at 20Hz. >> >> > >> >> > Currently Hyper-V only takes a physical address from guest as the starting >> >> > address of frame buffer. This implies the guest must allocate contiguous >> >> > physical memory for frame buffer. In addition, Hyper-V Gen 2 VMs only >> >> > accept address from MMIO region as frame buffer address. Due to these >> >> > limitations on Hyper-V host, we keep a shadow copy of frame buffer >> >> > in the guest. This means one more copy of the dirty rectangle inside >> >> > guest when doing the on-demand refresh. This can be optimized in the >> >> > future with help from host. For now the host performance gain from >> deferred >> >> > IO outweighs the shadow copy impact in the guest. >> >> > >> >> > Signed-off-by: Wei Hu >> > >> >Sasha -- this patch and one other from Wei Hu for the Hyper-V frame buffer >> >driver should be ready. Both patches affect only the Hyper-V frame buffer >> >driver so can go through the Hyper-V tree. Can you pick these up? Thx. >> >> I can't get this to apply anywhere, what tree is it based on? >> >> -- >> Thanks, >> Sasha > >Hi Sasha, >Today's hyperv/linux.git's hyperv-next branch's top commit is > 48b72a2697d5 ("hv_netvsc: Add the support of hibernation"). > >Please pick up two patches from Wei Hu: >#1: [PATCH v4] video: hyperv: hyperv_fb: Obtain screen resolution from Hyper-V host >#2: [PATHC v6] video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver Ah, I guess I was missing the first one. I've queued both for hyperv-next, thanks! -- Thanks, Sasha