From: Dan Williams <dan.j.williams@intel.com>
To: linux-nvdimm@lists.01.org
Cc: Tony Luck <tony.luck@intel.com>,
x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
linux-fsdevel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
hch@lst.de, linux-edac@vger.kernel.org
Subject: [PATCH v6 11/13] x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses
Date: Fri, 13 Jul 2018 21:50:27 -0700 [thread overview]
Message-ID: <153154382700.34503.10197588570935341739.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <153154376846.34503.15480221419473501643.stgit@dwillia2-desk3.amr.corp.intel.com>
In preparation for using set_memory_uc() instead set_memory_np() for
isolating poison from speculation, teach the memtype code to sanitize
physical addresses vs __PHYSICAL_MASK.
The motivation for using set_memory_uc() for this case is to allow
ongoing access to persistent memory pages via the pmem-driver +
memcpy_mcsafe() until the poison is repaired.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: <linux-edac@vger.kernel.org>
Cc: <x86@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
arch/x86/mm/pat.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 1555bd7d3449..6788ffa990f8 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -512,6 +512,17 @@ static int free_ram_pages_type(u64 start, u64 end)
return 0;
}
+static u64 sanitize_phys(u64 address)
+{
+ /*
+ * When changing the memtype for pages containing poison allow
+ * for a "decoy" virtual address (bit 63 clear) passed to
+ * set_memory_X(). __pa() on a "decoy" address results in a
+ * physical address with it 63 set.
+ */
+ return address & __PHYSICAL_MASK;
+}
+
/*
* req_type typically has one of the:
* - _PAGE_CACHE_MODE_WB
@@ -533,6 +544,8 @@ int reserve_memtype(u64 start, u64 end, enum page_cache_mode req_type,
int is_range_ram;
int err = 0;
+ start = sanitize_phys(start);
+ end = sanitize_phys(end);
BUG_ON(start >= end); /* end is exclusive */
if (!pat_enabled()) {
@@ -609,6 +622,9 @@ int free_memtype(u64 start, u64 end)
if (!pat_enabled())
return 0;
+ start = sanitize_phys(start);
+ end = sanitize_phys(end);
+
/* Low ISA region is always mapped WB. No need to track */
if (x86_platform.is_untracked_pat_range(start, end))
return 0;
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next prev parent reply other threads:[~2018-07-14 5:00 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-14 4:49 [PATCH v6 00/13] mm: Teach memory_failure() about ZONE_DEVICE pages Dan Williams
2018-07-14 4:49 ` [PATCH v6 01/13] device-dax: Convert to vmf_insert_mixed and vm_fault_t Dan Williams
2018-07-14 4:49 ` [PATCH v6 02/13] device-dax: Enable page_mapping() Dan Williams
2018-07-14 4:49 ` [PATCH v6 03/13] device-dax: Set page->index Dan Williams
2018-07-14 4:49 ` [PATCH v6 04/13] filesystem-dax: " Dan Williams
2018-07-14 4:49 ` [PATCH v6 05/13] mm, madvise_inject_error: Disable MADV_SOFT_OFFLINE for ZONE_DEVICE pages Dan Williams
2018-07-17 6:47 ` Naoya Horiguchi
2018-07-14 4:50 ` [PATCH v6 06/13] mm, dev_pagemap: Do not clear ->mapping on final put Dan Williams
2018-07-23 16:12 ` Dave Jiang
2018-07-23 16:23 ` Jerome Glisse
2018-07-14 4:50 ` [PATCH v6 07/13] mm, madvise_inject_error: Let memory_failure() optionally take a page reference Dan Williams
2018-07-17 6:52 ` Naoya Horiguchi
2018-07-14 4:50 ` [PATCH v6 08/13] mm, memory_failure: Collect mapping size in collect_procs() Dan Williams
2018-07-14 4:50 ` [PATCH v6 09/13] filesystem-dax: Introduce dax_lock_mapping_entry() Dan Williams
2018-08-06 9:21 ` Jan Kara
2018-07-14 4:50 ` [PATCH v6 10/13] mm, memory_failure: Teach memory_failure() about dev_pagemap pages Dan Williams
2018-08-06 9:27 ` Jan Kara
2018-07-14 4:50 ` Dan Williams [this message]
2018-07-24 7:36 ` [PATCH v6 11/13] x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses Ingo Molnar
2018-07-24 15:46 ` Dave Jiang
2018-07-14 4:50 ` [PATCH v6 12/13] x86/memory_failure: Introduce {set, clear}_mce_nospec() Dan Williams
2018-07-14 4:50 ` [PATCH v6 13/13] libnvdimm, pmem: Restore page attributes when clearing errors Dan Williams
2018-07-19 17:57 ` [PATCH v6 00/13] mm: Teach memory_failure() about ZONE_DEVICE pages Dave Jiang
2018-07-24 7:39 ` Ingo Molnar
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