From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH v1 2/5] libxc/trace: Add xc_tbuf_set_cpu_mask_array a variant of xc_tbuf_set_cpu_mask (v3) Date: Fri, 13 Jun 2014 14:30:50 -0400 Message-ID: <20140613183050.GD29076@laptop.dumpdata.com> References: <1401889471-1174-1-git-send-email-konrad.wilk@oracle.com> <1401889471-1174-3-git-send-email-konrad.wilk@oracle.com> <1401972575.15729.65.camel@hastur.hellion.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WvWFl-0005M3-PE for xen-devel@lists.xenproject.org; Fri, 13 Jun 2014 18:31:06 +0000 Content-Disposition: inline In-Reply-To: <1401972575.15729.65.camel@hastur.hellion.org.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: george.dunlap@eu.citrix.com, xen-devel@lists.xenproject.org, ian.jackson@eu.citrix.com, stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org On Thu, Jun 05, 2014 at 01:49:35PM +0100, Ian Campbell wrote: > On Wed, 2014-06-04 at 09:44 -0400, Konrad Rzeszutek Wilk wrote: > > which uses an xc_cpumap_t instead of a uint32_t. This means > > we can use an arbitrary bitmap without being limited to the > > 32-bits the xc_tbuf_set_cpu_mask_array can only do. > > We do not guarantee API stability for libxc, so it is OK to either fix > the existing one or replace it. No need to keep the old one around > (unless perhaps calling applications fall into two sets each of whom > finds a different interface best). > > > We also add an macro which can be used by both libxc and > > xentrace. > > > > Signed-off-by: Konrad Rzeszutek Wilk > > [v2: Use DIV_ROUND_UP macro as suggested by Daniel] > > [v3: Use 'int' for bits instead of 'unsigned int' as spotted by Boris] > > --- > > tools/libxc/xc_bitops.h | 2 ++ > > tools/libxc/xc_tbuf.c | 40 ++++++++++++++++++++++++++++++++++++++++ > > tools/libxc/xenctrl.h | 1 + > > 3 files changed, 43 insertions(+) > > > > diff --git a/tools/libxc/xc_bitops.h b/tools/libxc/xc_bitops.h > > index d8e0c16..b8cf2bd 100644 > > --- a/tools/libxc/xc_bitops.h > > +++ b/tools/libxc/xc_bitops.h > > @@ -12,6 +12,8 @@ > > #define BITMAP_ENTRY(_nr,_bmap) ((_bmap))[(_nr)/BITS_PER_LONG] > > #define BITMAP_SHIFT(_nr) ((_nr) % BITS_PER_LONG) > > > > +#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) > > This isn't really a bitops.h thing, xc_private.h seems like the usual > dumping ground for stuff which doesn't fit elsewhere. > > > +int xc_tbuf_set_cpu_mask_array(xc_interface *xch, xc_cpumap_t mask, int bits) > > +{ > > + DECLARE_SYSCTL; > > + DECLARE_HYPERCALL_BUFFER(uint8_t, bytemap); > > + int ret = -1; > > + int local_bits; > > + > > + if ( bits <= 0 ) > > + goto out; > > + > > + local_bits = xc_get_max_cpus(xch); > > + if ( bits > local_bits ) > > + { > > + PERROR("Wrong amount of bits supplied: %u, using %u\n", bits, local_bits); > > Should we not just return an error? > > > + bits = local_bits; > > + } > > + bytemap = xc_hypercall_buffer_alloc(xch, bytemap, DIV_ROUND_UP(bits, 8)); > > + if ( bytemap == NULL ) > > + { > > + PERROR("Could not allocate memory for xc_tbuf_set_cpu_mask_array hypercall"); > > + goto out; > > + } > > + > > + memcpy(bytemap, mask, DIV_ROUND_UP(bits, 8)); > > Take a look at Dario's "libxc: get and set soft and hard affinity"[0] > for how to do this using the hypercall bounce buffer interface. > > [0] <1401237770-7003-6-git-send-email-dario.faggioli@citrix.com> Since George asked me to merge two patches (libxc + xentrace) and also throw out the old xc_tbuf_set_cpu_mask, would you be OK if this was a seperate commit? Too many things going in the patch already. > > Ian. > > > + > > + sysctl.cmd = XEN_SYSCTL_tbuf_op; > > + sysctl.interface_version = XEN_SYSCTL_INTERFACE_VERSION; > > + sysctl.u.tbuf_op.cmd = XEN_SYSCTL_TBUFOP_set_cpu_mask; > > + > > + set_xen_guest_handle(sysctl.u.tbuf_op.cpu_mask.bitmap, bytemap); > > + sysctl.u.tbuf_op.cpu_mask.nr_bits = bits; > > + > > + ret = do_sysctl(xch, &sysctl); > > + > > + xc_hypercall_buffer_free(xch, bytemap); > > + > > + out: > > + return ret; > > +} > > > > int xc_tbuf_set_evt_mask(xc_interface *xch, uint32_t mask) > > { > >