From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kai Huang Subject: [v3 01/10] vmx: add new boot parameter to control PML enabling Date: Fri, 24 Apr 2015 16:19:29 +0800 Message-ID: <1429863578-16741-2-git-send-email-kai.huang@linux.intel.com> References: <1429863578-16741-1-git-send-email-kai.huang@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1429863578-16741-1-git-send-email-kai.huang@linux.intel.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.cooper3@citrix.com, tim@xen.org, jbeulich@suse.com, kevin.tian@intel.com, xen-devel@lists.xen.org Cc: Kai Huang List-Id: xen-devel@lists.xenproject.org A top level EPT parameter "ept=" and a sub boolean "opt_pml_enabled" are added to control PML. Other booleans can be further added for any other EPT related features. The document description for the new parameter is also added. Signed-off-by: Kai Huang --- docs/misc/xen-command-line.markdown | 15 +++++++++++++++ xen/arch/x86/hvm/vmx/vmcs.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+) diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown index 1dda1f0..4889e27 100644 --- a/docs/misc/xen-command-line.markdown +++ b/docs/misc/xen-command-line.markdown @@ -685,6 +685,21 @@ requirement can be relaxed. This option is particularly useful for nested virtualization, to allow the L1 hypervisor to use EPT even if the L0 hypervisor does not provide VM\_ENTRY\_LOAD\_GUEST\_PAT. +### ept (Intel) +> `= List of ( pml )` + +> Default: `false` + +Controls EPT related features. Currently only Page Modification Logging (PML) is +the controllable feature as boolean type. + +PML is a new hardware feature in Intel's Broadwell Server and further platforms +which reduces hypervisor overhead of log-dirty mechanism by automatically +recording GPAs (guest physical addresses) when guest memory gets dirty, and +therefore significantly reducing number of EPT violation caused by write +protection of guest memory, which is a necessity to implement log-dirty +mechanism before PML. + ### gdb > `= [/][,DPS[,[,[,[,]]]] | pci | amt ] ` diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c index 63007a9..79efa42 100644 --- a/xen/arch/x86/hvm/vmx/vmcs.c +++ b/xen/arch/x86/hvm/vmx/vmcs.c @@ -64,6 +64,36 @@ integer_param("ple_gap", ple_gap); static unsigned int __read_mostly ple_window = 4096; integer_param("ple_window", ple_window); +static bool_t __read_mostly opt_pml_enabled = 0; + +/* + * The 'ept' parameter controls functionalities that depend on, or impact the + * EPT mechanism. Optional comma separated value may contain: + * + * pml Enable PML + */ +static void __init parse_ept_param(char *s) +{ + char *ss; + + do { + bool_t val = !!strncmp(s, "no-", 3); + if ( !val ) + s += 3; + + ss = strchr(s, ','); + if ( ss ) + *ss = '\0'; + + if ( !strcmp(s, "pml") ) + opt_pml_enabled = val; + + s = ss + 1; + } while ( ss ); +} + +custom_param("ept", parse_ept_param); + /* Dynamic (run-time adjusted) execution control flags. */ u32 vmx_pin_based_exec_control __read_mostly; u32 vmx_cpu_based_exec_control __read_mostly; -- 2.1.0