From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: [PATCH] tools/libxc: Avoid hypercalls for cacheflush on x86 Date: Mon, 3 Mar 2014 14:37:58 +0000 Message-ID: <1393857478-14993-1-git-send-email-andrew.cooper3@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Xen-devel Cc: Andrew Cooper , Ian Jackson , Ian Campbell List-Id: xen-devel@lists.xenproject.org XEN_DOMCTL_cacheflush hypercalls are -ENOSYS on x86. As domain creation/migration is already very hypercall-heavy, avoid making extra redundant hypercalls Signed-off-by: Andrew Cooper CC: Ian Campbell CC: Ian Jackson --- Discovered when running valgrind against XenServer trunk, which is now 4.4 based. --- tools/libxc/xc_domain.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c index 369c3f3..b9cc1db 100644 --- a/tools/libxc/xc_domain.c +++ b/tools/libxc/xc_domain.c @@ -51,12 +51,18 @@ int xc_domain_create(xc_interface *xch, int xc_domain_cacheflush(xc_interface *xch, uint32_t domid, xen_pfn_t start_pfn, xen_pfn_t nr_pfns) { +#if defined (__i386__) || defined (__x86_64__) + /* This is not implemented or needed for x86. Avoid repeatedly going to + * Xen to find -ENOSYS. */ + return -ENOSYS; +#else DECLARE_DOMCTL; domctl.cmd = XEN_DOMCTL_cacheflush; domctl.domain = (domid_t)domid; domctl.u.cacheflush.start_pfn = start_pfn; domctl.u.cacheflush.nr_pfns = nr_pfns; return do_domctl(xch, &domctl); +#endif } int xc_domain_pause(xc_interface *xch, -- 1.7.10.4