From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ed White Subject: Re: [PATCH 02/11] VMX: implement suppress #VE. Date: Wed, 25 Mar 2015 10:30:17 -0700 Message-ID: <5512F0A9.20000@intel.com> References: <1420838801-11704-1-git-send-email-edmund.h.white@intel.com> <1420838801-11704-3-git-send-email-edmund.h.white@intel.com> <20150115162506.GB57240@deinos.phlegethon.org> <54B80B1A.3050707@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <54B80B1A.3050707@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: Tim Deegan Cc: keir@xen.org, ian.jackson@eu.citrix.com, ian.campbell@citrix.com, jbeulich@suse.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 01/15/2015 10:46 AM, Ed White wrote: > On 01/15/2015 08:25 AM, Tim Deegan wrote: >> Hi, >> >> At 13:26 -0800 on 09 Jan (1420806392), Ed White wrote: >>> static inline bool_t is_epte_valid(ept_entry_t *e) >>> { >>> - return (e->epte != 0 && e->sa_p2mt != p2m_invalid); >>> + return (e->valid != 0 && e->sa_p2mt != p2m_invalid); >> >> This test for 0 is just catching uninitialised entries in freshly >> allocated pages. Rather than changing it to ignore bit 63, this loop... >> >>> } >>> >>> /* returns : 0 for success, -errno otherwise */ >>> @@ -194,6 +194,19 @@ static int ept_set_middle_entry(struct p2m_domain *p2m, ept_entry_t *ept_entry) >>> >>> ept_entry->r = ept_entry->w = ept_entry->x = 1; >>> >>> + /* Disable #VE on all entries */ >>> + if ( cpu_has_vmx_virt_exceptions ) >>> + { >>> + ept_entry_t *table = __map_domain_page(pg); >>> + >>> + for ( int i = 0; i < EPT_PAGETABLE_ENTRIES; i++ ) >>> + table[i].suppress_ve = 1; >> >> ...should set the type of the empty entries to p2m_invalid as it goes. >> >>> + /* Disable #VE on all entries */ >>> + if ( cpu_has_vmx_virt_exceptions ) >>> + { >>> + ept_entry_t *table = >>> + map_domain_page(pagetable_get_pfn(p2m_get_pagetable(p2m))); >>> + >>> + for ( int i = 0; i < EPT_PAGETABLE_ENTRIES; i++ ) >>> + table[i].suppress_ve = 1; >> >> And the same here. I have some time to work on this patch series again, and although I tried this it doesn't eliminate all the instances of epte being zero with the possible exception of suppress_ve. I spent some time trying to find all cases where that happens without success, so I've used Andrew's suggestion of using a mask. Ed