diff options
author | Li, Zhen-Hua <zhen-hual@hp.com> | 2014-11-05 08:30:19 +0100 |
---|---|---|
committer | Joerg Roedel <jroedel@suse.de> | 2014-11-06 14:40:10 +0100 |
commit | 1a2262f90f493103496f3383741fb5d594c33738 (patch) | |
tree | c039b0b57766843c631deb690ce96c75c01d4681 /drivers/iommu | |
parent | Linux 3.18-rc3 (diff) | |
download | linux-1a2262f90f493103496f3383741fb5d594c33738.tar.xz linux-1a2262f90f493103496f3383741fb5d594c33738.zip |
x86/vt-d: Fix incorrect bit operations in setting values
The function context_set_address_root() and set_root_value are setting new
address in a wrong way, and this patch is trying to fix this problem.
According to Intel Vt-d specs(Feb 2011, Revision 1.3), Chapter 9.1 and 9.2,
field ctp in root entry is using bits 12:63, field asr in context entry is
using bits 12:63.
To set these fields, the following functions are used:
static inline void context_set_address_root(struct context_entry *context,
unsigned long value);
and
static inline void set_root_value(struct root_entry *root, unsigned long value)
But they are using an invalid method to set these fields, in current code, only
a '|' operator is used to set it. This will not set the asr to the expected
value if it has an old value.
For example:
Before calling this function,
context->lo = 0x3456789012111;
value = 0x123456789abcef12;
After we call context_set_address_root(context, value), expected result is
context->lo == 0x123456789abce111;
But the actual result is:
context->lo == 0x1237577f9bbde111;
So we need to clear bits 12:63 before setting the new value, this will fix
this problem.
Signed-off-by: Li, Zhen-Hua <zhen-hual@hp.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r-- | drivers/iommu/intel-iommu.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index a27d6cb1a793..ba0fa2a8d696 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -195,6 +195,7 @@ static inline void set_root_present(struct root_entry *root) } static inline void set_root_value(struct root_entry *root, unsigned long value) { + root->val &= ~VTD_PAGE_MASK; root->val |= value & VTD_PAGE_MASK; } @@ -247,6 +248,7 @@ static inline void context_set_translation_type(struct context_entry *context, static inline void context_set_address_root(struct context_entry *context, unsigned long value) { + context->lo &= ~VTD_PAGE_MASK; context->lo |= value & VTD_PAGE_MASK; } |