diff options
Diffstat (limited to '0027-x86-EPT-avoid-marking-non-present-entries-for-re-con.patch')
| -rw-r--r-- | 0027-x86-EPT-avoid-marking-non-present-entries-for-re-con.patch | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/0027-x86-EPT-avoid-marking-non-present-entries-for-re-con.patch b/0027-x86-EPT-avoid-marking-non-present-entries-for-re-con.patch new file mode 100644 index 0000000..23e8946 --- /dev/null +++ b/0027-x86-EPT-avoid-marking-non-present-entries-for-re-con.patch @@ -0,0 +1,85 @@ +From d31385be5c8e8bc5efb6f8848057bd0c69e8274a Mon Sep 17 00:00:00 2001 +From: Jan Beulich <jbeulich@suse.com> +Date: Wed, 26 Jun 2024 13:40:11 +0200 +Subject: [PATCH 27/56] x86/EPT: avoid marking non-present entries for + re-configuring +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +For non-present entries EMT, like most other fields, is meaningless to +hardware. Make the logic in ept_set_entry() setting the field (and iPAT) +conditional upon dealing with a present entry, leaving the value at 0 +otherwise. This has two effects for epte_get_entry_emt() which we'll +want to leverage subsequently: +1) The call moved here now won't be issued with INVALID_MFN anymore (a + respective BUG_ON() is being added). +2) Neither of the other two calls could now be issued with a truncated + form of INVALID_MFN anymore (as long as there's no bug anywhere + marking an entry present when that was populated using INVALID_MFN). + +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> +master commit: 777c71d31325bc55ba1cc3f317d4155fe519ab0b +master date: 2024-06-13 16:54:17 +0200 +--- + xen/arch/x86/mm/p2m-ept.c | 29 ++++++++++++++++++----------- + 1 file changed, 18 insertions(+), 11 deletions(-) + +diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c +index 1aa6bbc771..641d61b350 100644 +--- a/xen/arch/x86/mm/p2m-ept.c ++++ b/xen/arch/x86/mm/p2m-ept.c +@@ -649,6 +649,8 @@ static int cf_check resolve_misconfig(struct p2m_domain *p2m, unsigned long gfn) + if ( e.emt != MTRR_NUM_TYPES ) + break; + ++ ASSERT(is_epte_present(&e)); ++ + if ( level == 0 ) + { + for ( gfn -= i, i = 0; i < EPT_PAGETABLE_ENTRIES; ++i ) +@@ -914,17 +916,6 @@ ept_set_entry(struct p2m_domain *p2m, gfn_t gfn_, mfn_t mfn, + + if ( mfn_valid(mfn) || p2m_allows_invalid_mfn(p2mt) ) + { +- bool ipat; +- int emt = epte_get_entry_emt(p2m->domain, _gfn(gfn), mfn, +- i * EPT_TABLE_ORDER, &ipat, +- p2mt); +- +- if ( emt >= 0 ) +- new_entry.emt = emt; +- else /* ept_handle_misconfig() will need to take care of this. */ +- new_entry.emt = MTRR_NUM_TYPES; +- +- new_entry.ipat = ipat; + new_entry.sp = !!i; + new_entry.sa_p2mt = p2mt; + new_entry.access = p2ma; +@@ -940,6 +931,22 @@ ept_set_entry(struct p2m_domain *p2m, gfn_t gfn_, mfn_t mfn, + need_modify_vtd_table = 0; + + ept_p2m_type_to_flags(p2m, &new_entry); ++ ++ if ( is_epte_present(&new_entry) ) ++ { ++ bool ipat; ++ int emt = epte_get_entry_emt(p2m->domain, _gfn(gfn), mfn, ++ i * EPT_TABLE_ORDER, &ipat, ++ p2mt); ++ ++ BUG_ON(mfn_eq(mfn, INVALID_MFN)); ++ ++ if ( emt >= 0 ) ++ new_entry.emt = emt; ++ else /* ept_handle_misconfig() will need to take care of this. */ ++ new_entry.emt = MTRR_NUM_TYPES; ++ new_entry.ipat = ipat; ++ } + } + + if ( sve != -1 ) +-- +2.45.2 + |