From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony PERARD Subject: Re: [RFC PATCH 0/5] Load BIOS via toolstack instead of been embedded in hvmloader. Date: Thu, 17 Sep 2015 10:49:10 +0100 Message-ID: <20150917094910.GD2104@perard.uk.xensource.com> References: <1442423987-14956-1-git-send-email-anthony.perard@citrix.com> <55F9BB6C.4020404@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <55F9BB6C.4020404@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andrew Cooper Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Wed, Sep 16, 2015 at 07:56:44PM +0100, Andrew Cooper wrote: > On 16/09/2015 18:19, Anthony PERARD wrote: > > Hi all, > > > > I've start to look at loading the BIOS and the ACPI tables via the > > toolstack instead of having them embedded in the hvmloader binary. This is > > done by using the same mechanics as the one used to load extra ACPI tables > > or SMBIOS. > > > > - libxl load the blob into it's memory and add it to > > struct xc_hvm_build_args.bios_module > > - libxc load the blob into the guest memory and give back the guest address > > of the blob. > > - libxl store the location of the blob (and it's lenght) into xenstore, in > > /local/domain/$domid/hvmloader/$blob_name/{address,length} ($blob_name > > would be "bios" or "acpi_table"; there is already "acpi" and "smbios" > > that exist) > > - hvmloader read the addresses from xenstore and put the blob at the right > > place. > > > > How this is looking? > > > > Right now, this patch series would only work for SeaBIOS. > > I highly recommend that you build on top of Rogers DMlite series, which > already offers a multiboot-style way of adding extra modules to HVM > guests. (That was the way I was planning to do this in some copious > free time). Thanks. I will look into this. > In particular, storing the address/length in xenstore is conceptually > incorrect as the information turns stale as soon as hvmloader starts > running. > > * Modify hvmloader to have a DMLite entry, which gives it a command line > and module list > * Modify libxc to be able to take an arbitrary quantity of modules, > rather than the currently limit of 1 > > Once the above work times are in place, the actual splitting-up of > hvmloader can occur. > > I recommend a command line way of telling hvmloader which module is > what, such as a legacy bios image, (other firmware image?), supplemental > acpi table, supplemental smbios table, nvram blob? (This last one will > require a bit of extra work so the toolstack can pull the blob back out > of the guest on destruction) -- Anthony PERARD