From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: [PATCH v2] xen: arm: correctly handle continuations for 64-bit guests Date: Mon, 30 Mar 2015 10:07:38 +0100 Message-ID: <1427706458.13935.221.camel@citrix.com> References: <1427367244-419-1-git-send-email-ian.campbell@citrix.com> <5513F45C.50609@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5513F45C.50609@linaro.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall Cc: stefano.stabellini@eu.citrix.com, tim@xen.org, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Thu, 2015-03-26 at 11:58 +0000, Julien Grall wrote: > Hi Ian, > > On 26/03/2015 10:54, Ian Campbell wrote: > > The 64-bit ABI is different to 32-bit: > > > > - uses x16 as the op register rather than r12. > > - arguments in x0..x5 and not r0..r5. Using rN here potentially > > truncates. > > - return value goes in x0, not r0. > > > > Hypercalls can only be made directly from kernel space, so checking > > the domain's size is sufficient. > > > > Spotted due to spurious -EFAULT when destroying a domain, due to the > > hypercall's pointer argument being truncated. I'm unclear why I am > > only seeing this now. > > > > Signed-off-by: Ian Campbell > > Reviewed-by: Julien Grall > > --- > > I imagine this needs backporting everywhere... > > > > v2: Pull regs->pc update out of the conditional blocks, no need to > > mess around with thumb. > > FWIW, with this change I confirm my Reviewed-by. Thanks, applied. Ian.