From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Peng Subject: Re: [PATCH 2/4] tools: libxc: add routine to get CMT L3 event mask Date: Wed, 24 Dec 2014 16:33:48 +0800 Message-ID: <20141224083348.GA10595@pengc-linux.bj.intel.com> References: <1419324880-13212-1-git-send-email-chao.p.peng@linux.intel.com> <1419324880-13212-3-git-send-email-chao.p.peng@linux.intel.com> <54998E61.8020103@citrix.com> Reply-To: Chao Peng Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <54998E61.8020103@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: keir@xen.org, Ian.Campbell@citrix.com, stefano.stabellini@eu.citrix.com, Ian.Jackson@eu.citrix.com, xen-devel@lists.xen.org, JBeulich@suse.com, wei.liu2@citrix.com List-Id: xen-devel@lists.xenproject.org On Tue, Dec 23, 2014 at 03:46:41PM +0000, Andrew Cooper wrote: > > On 23/12/2014 08:54, Chao Peng wrote: > >This is the xc side wrapper for XEN_SYSCTL_PSR_CMT_get_l3_event_mask > >of XEN_SYSCTL_psr_cmt_op. Additional check for event id against value > >got from this routine is also added. > > > >Signed-off-by: Chao Peng > >--- > > tools/libxc/include/xenctrl.h | 1 + > > tools/libxc/xc_psr.c | 32 ++++++++++++++++++++++++++++++++ > > 2 files changed, 33 insertions(+) > > > >diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h > >index 0ad8b8d..96b357c 100644 > >--- a/tools/libxc/include/xenctrl.h > >+++ b/tools/libxc/include/xenctrl.h > >@@ -2697,6 +2697,7 @@ int xc_psr_cmt_get_domain_rmid(xc_interface *xch, uint32_t domid, > > int xc_psr_cmt_get_total_rmid(xc_interface *xch, uint32_t *total_rmid); > > int xc_psr_cmt_get_l3_upscaling_factor(xc_interface *xch, > > uint32_t *upscaling_factor); > >+int xc_psr_cmt_get_l3_event_mask(xc_interface *xch, uint32_t *event_mask); > > int xc_psr_cmt_get_l3_cache_size(xc_interface *xch, uint32_t cpu, > > uint32_t *l3_cache_size); > > int xc_psr_cmt_get_data(xc_interface *xch, uint32_t rmid, > >diff --git a/tools/libxc/xc_psr.c b/tools/libxc/xc_psr.c > >index 872e6dc..94c8698 100644 > >--- a/tools/libxc/xc_psr.c > >+++ b/tools/libxc/xc_psr.c > >@@ -112,6 +112,30 @@ int xc_psr_cmt_get_l3_upscaling_factor(xc_interface *xch, > > return rc; > > } > >+int xc_psr_cmt_get_l3_event_mask(xc_interface *xch, uint32_t *event_mask) > >+{ > >+ static int val = 0; > >+ int rc; > >+ DECLARE_SYSCTL; > >+ > >+ if ( val ) > >+ { > >+ *event_mask = val; > >+ return 0; > >+ } > >+ > >+ sysctl.cmd = XEN_SYSCTL_psr_cmt_op; > >+ sysctl.u.psr_cmt_op.cmd = > >+ XEN_SYSCTL_PSR_CMT_get_l3_event_mask; > >+ sysctl.u.psr_cmt_op.flags = 0; > >+ > >+ rc = xc_sysctl(xch, &sysctl); > >+ if ( !rc ) > >+ val = *event_mask = sysctl.u.psr_cmt_op.u.data; > >+ > >+ return rc; > >+} > >+ > > int xc_psr_cmt_get_l3_cache_size(xc_interface *xch, uint32_t cpu, > > uint32_t *l3_cache_size) > > { > >@@ -144,6 +168,7 @@ int xc_psr_cmt_get_data(xc_interface *xch, uint32_t rmid, > > xc_resource_op_t op; > > xc_resource_entry_t entries[2]; > > uint32_t evtid; > >+ uint32_t event_mask; > > int rc; > > switch ( type ) > >@@ -155,6 +180,13 @@ int xc_psr_cmt_get_data(xc_interface *xch, uint32_t rmid, > > return -1; > > } > >+ rc = xc_psr_cmt_get_l3_event_mask(xch, &event_mask); > >+ if ( rc < 0 ) > >+ return rc; > >+ > >+ if ( !(event_mask & (1 << (evtid - 1))) ) > >+ return -1; > >+ > > This adds an extra hypercall on a common path to return a constant. As libxc > is mostly a set of basic hypercall wrappers, I don't it should be validating > its parameters like this. > > The caller of xc_psr_cmt_get_data() must be aware of all the details, and > whether certain events are supported or not. I woud simply let the > xc_resourse_op() fail (faulting on the wrmsr) if the caller passes a bad > event id. > Sounds reasonable. I'd move the validation to the caller, that's, the xl side. Thanks Andrew. > > > entries[0].u.cmd = XEN_RESOURCE_OP_MSR_WRITE; > > entries[0].idx = MSR_IA32_CMT_EVTSEL; > > entries[0].val = (uint64_t)rmid << 32 | evtid; > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel