From: Dave Hansen <dave.hansen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, dave.hansen@linux.intel.com,
moritz.lipp@iaik.tugraz.at, daniel.gruss@iaik.tugraz.at,
michael.schwarz@iaik.tugraz.at, luto@kernel.org,
torvalds@linux-foundation.org, keescook@google.com,
hughd@google.com, x86@kernel.org
Subject: [PATCH 20/23] x86, mm: put mmu-to-h/w ASID translation in one place
Date: Tue, 31 Oct 2017 15:32:22 -0700 [thread overview]
Message-ID: <20171031223222.E3E7D650@viggo.jf.intel.com> (raw)
In-Reply-To: <20171031223146.6B47C861@viggo.jf.intel.com>
We effectively have two ASID types:
1. The one stored in the mmu_context that goes from 0->5
2. The one we program into the hardware that goes from 1->6
Let's just put the +1 in a single place which gives us a
nice place to comment. KAISER will also need to, given an
ASID, know which hardware ASID to flush for the userspace
mapping.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
Cc: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
Cc: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kees Cook <keescook@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: x86@kernel.org
---
b/arch/x86/include/asm/tlbflush.h | 30 ++++++++++++++++++------------
1 file changed, 18 insertions(+), 12 deletions(-)
diff -puN arch/x86/include/asm/tlbflush.h~kaiser-pcid-pre-build-kern arch/x86/include/asm/tlbflush.h
--- a/arch/x86/include/asm/tlbflush.h~kaiser-pcid-pre-build-kern 2017-10-31 15:03:59.699555275 -0700
+++ b/arch/x86/include/asm/tlbflush.h 2017-10-31 15:03:59.703555465 -0700
@@ -86,21 +86,26 @@ static inline u64 inc_mm_tlb_gen(struct
*/
#define NR_AVAIL_ASIDS ((1<<CR3_AVAIL_ASID_BITS) - 1)
-/*
- * If PCID is on, ASID-aware code paths put the ASID+1 into the PCID
- * bits. This serves two purposes. It prevents a nasty situation in
- * which PCID-unaware code saves CR3, loads some other value (with PCID
- * == 0), and then restores CR3, thus corrupting the TLB for ASID 0 if
- * the saved ASID was nonzero. It also means that any bugs involving
- * loading a PCID-enabled CR3 with CR4.PCIDE off will trigger
- * deterministically.
- */
+static inline u16 kern_asid(u16 asid)
+{
+ VM_WARN_ON_ONCE(asid >= NR_AVAIL_ASIDS);
+ /*
+ * If PCID is on, ASID-aware code paths put the ASID+1 into the PCID
+ * bits. This serves two purposes. It prevents a nasty situation in
+ * which PCID-unaware code saves CR3, loads some other value (with PCID
+ * == 0), and then restores CR3, thus corrupting the TLB for ASID 0 if
+ * the saved ASID was nonzero. It also means that any bugs involving
+ * loading a PCID-enabled CR3 with CR4.PCIDE off will trigger
+ * deterministically.
+ */
+ return asid + 1;
+}
+
struct pgd_t;
static inline unsigned long build_cr3(pgd_t *pgd, u16 asid)
{
if (static_cpu_has(X86_FEATURE_PCID)) {
- VM_WARN_ON_ONCE(asid > NR_AVAIL_ASIDS);
- return __sme_pa(pgd) | (asid + 1);
+ return __sme_pa(pgd) | kern_asid(asid);
} else {
VM_WARN_ON_ONCE(asid != 0);
return __sme_pa(pgd);
@@ -110,7 +115,8 @@ static inline unsigned long build_cr3(pg
static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid)
{
VM_WARN_ON_ONCE(asid > NR_AVAIL_ASIDS);
- return __sme_pa(pgd) | (asid + 1) | CR3_NOFLUSH;
+ VM_WARN_ON_ONCE(!this_cpu_has(X86_FEATURE_PCID));
+ return __sme_pa(pgd) | kern_asid(asid) | CR3_NOFLUSH;
}
#ifdef CONFIG_PARAVIRT
_
next prev parent reply other threads:[~2017-10-31 22:33 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-31 22:31 [PATCH 00/23] KAISER: unmap most of the kernel from userspace page tables Dave Hansen
2017-10-31 22:31 ` [PATCH 01/23] x86, kaiser: prepare assembly for entry/exit CR3 switching Dave Hansen
2017-11-01 0:43 ` Brian Gerst
2017-11-01 1:08 ` Dave Hansen
2017-11-01 18:18 ` Borislav Petkov
2017-11-01 18:27 ` Dave Hansen
2017-11-01 20:42 ` Borislav Petkov
2017-11-01 21:01 ` Thomas Gleixner
2017-11-01 22:58 ` Dave Hansen
2017-10-31 22:31 ` [PATCH 02/23] x86, kaiser: do not set _PAGE_USER for init_mm page tables Dave Hansen
2017-11-01 21:11 ` Thomas Gleixner
2017-11-01 21:24 ` Andy Lutomirski
2017-11-01 21:28 ` Thomas Gleixner
2017-11-01 21:52 ` Dave Hansen
2017-11-01 22:11 ` Thomas Gleixner
2017-11-01 22:12 ` Linus Torvalds
2017-11-01 22:20 ` Thomas Gleixner
2017-11-01 22:45 ` Kees Cook
2017-11-02 7:10 ` Andy Lutomirski
2017-11-02 11:33 ` Thomas Gleixner
2017-11-02 11:59 ` Andy Lutomirski
2017-11-02 12:56 ` Thomas Gleixner
2017-11-02 16:38 ` Dave Hansen
2017-11-02 18:19 ` Andy Lutomirski
2017-11-02 18:24 ` Thomas Gleixner
2017-11-02 18:24 ` Linus Torvalds
2017-11-02 18:40 ` Thomas Gleixner
2017-11-02 18:57 ` Linus Torvalds
2017-11-02 21:41 ` Thomas Gleixner
2017-11-02 7:07 ` Andy Lutomirski
2017-11-02 11:21 ` Thomas Gleixner
2017-10-31 22:31 ` [PATCH 03/23] x86, kaiser: disable global pages Dave Hansen
2017-11-01 21:18 ` Thomas Gleixner
2017-11-01 22:12 ` Dave Hansen
2017-11-01 22:28 ` Thomas Gleixner
2017-10-31 22:31 ` [PATCH 04/23] x86, tlb: make CR4-based TLB flushes more robust Dave Hansen
2017-11-01 8:01 ` Andy Lutomirski
2017-11-01 10:11 ` Kirill A. Shutemov
2017-11-01 10:38 ` Andy Lutomirski
2017-11-01 10:56 ` Kirill A. Shutemov
2017-11-01 11:18 ` Andy Lutomirski
2017-11-01 22:21 ` Dave Hansen
2017-11-01 21:25 ` Thomas Gleixner
2017-11-01 22:24 ` Dave Hansen
2017-11-01 22:30 ` Thomas Gleixner
2017-10-31 22:31 ` [PATCH 05/23] x86, mm: document X86_CR4_PGE toggling behavior Dave Hansen
2017-10-31 23:31 ` Kees Cook
2017-10-31 22:31 ` [PATCH 06/23] x86, kaiser: introduce user-mapped percpu areas Dave Hansen
2017-11-01 21:47 ` Thomas Gleixner
2017-10-31 22:31 ` [PATCH 07/23] x86, kaiser: unmap kernel from userspace page tables (core patch) Dave Hansen
2017-10-31 22:32 ` [PATCH 08/23] x86, kaiser: only populate shadow page tables for userspace Dave Hansen
2017-10-31 23:35 ` Kees Cook
2017-10-31 22:32 ` [PATCH 09/23] x86, kaiser: allow NX to be set in p4d/pgd Dave Hansen
2017-10-31 22:32 ` [PATCH 10/23] x86, kaiser: make sure static PGDs are 8k in size Dave Hansen
2017-10-31 22:32 ` [PATCH 11/23] x86, kaiser: map GDT into user page tables Dave Hansen
2017-10-31 22:32 ` [PATCH 12/23] x86, kaiser: map dynamically-allocated LDTs Dave Hansen
2017-11-01 8:00 ` Andy Lutomirski
2017-11-01 8:06 ` Ingo Molnar
2017-10-31 22:32 ` [PATCH 13/23] x86, kaiser: map espfix structures Dave Hansen
2017-10-31 22:32 ` [PATCH 14/23] x86, kaiser: map entry stack variables Dave Hansen
2017-10-31 22:32 ` [PATCH 15/23] x86, kaiser: map trace interrupt entry Dave Hansen
2017-10-31 22:32 ` [PATCH 16/23] x86, kaiser: map debug IDT tables Dave Hansen
2017-10-31 22:32 ` [PATCH 17/23] x86, kaiser: map virtually-addressed performance monitoring buffers Dave Hansen
2017-10-31 22:32 ` [PATCH 18/23] x86, mm: Move CR3 construction functions Dave Hansen
2017-10-31 22:32 ` [PATCH 19/23] x86, mm: remove hard-coded ASID limit checks Dave Hansen
2017-10-31 22:32 ` Dave Hansen [this message]
2017-10-31 22:32 ` [PATCH 21/23] x86, pcid, kaiser: allow flushing for future ASID switches Dave Hansen
2017-11-01 8:03 ` Andy Lutomirski
2017-11-01 14:17 ` Dave Hansen
2017-11-01 20:31 ` Andy Lutomirski
2017-11-01 20:59 ` Dave Hansen
2017-11-01 21:04 ` Andy Lutomirski
2017-11-01 21:06 ` Dave Hansen
2017-10-31 22:32 ` [PATCH 22/23] x86, kaiser: use PCID feature to make user and kernel switches faster Dave Hansen
2017-10-31 22:32 ` [PATCH 23/23] x86, kaiser: add Kconfig Dave Hansen
2017-10-31 23:59 ` Kees Cook
2017-11-01 9:07 ` Borislav Petkov
2017-10-31 23:27 ` [PATCH 00/23] KAISER: unmap most of the kernel from userspace page tables Linus Torvalds
2017-10-31 23:44 ` Dave Hansen
2017-11-01 0:21 ` Dave Hansen
2017-11-01 7:59 ` Andy Lutomirski
2017-11-01 16:08 ` Linus Torvalds
2017-11-01 17:31 ` Dave Hansen
2017-11-01 17:58 ` Randy Dunlap
2017-11-01 18:27 ` Linus Torvalds
2017-11-01 18:46 ` Dave Hansen
2017-11-01 19:05 ` Linus Torvalds
2017-11-01 20:33 ` Andy Lutomirski
2017-11-02 7:32 ` Andy Lutomirski
2017-11-02 7:54 ` Andy Lutomirski
2017-11-01 15:53 ` Dave Hansen
2017-11-01 8:54 ` Ingo Molnar
2017-11-01 14:09 ` Thomas Gleixner
2017-11-01 22:14 ` Dave Hansen
2017-11-01 22:28 ` Linus Torvalds
2017-11-02 8:03 ` Peter Zijlstra
2017-11-03 11:07 ` Kirill A. Shutemov
2017-11-02 19:01 ` Will Deacon
2017-11-02 19:38 ` Dave Hansen
2017-11-03 13:41 ` Will Deacon
2017-11-22 16:19 ` Pavel Machek
2017-11-23 10:47 ` Pavel Machek
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