Issue description:
-----------------
Machine Check Error on Page Size Change
Instruction fetch may cause machine check error if page size
and memory type was changed without invalidation on some
processors[1][2]. Malicious guest kernel could trigger this issue.
This issue applies to both primary page table and extended page
tables (EPT), however the primary page table is controlled by
hypervisor only. This patch mitigates the situation in EPT.
Mitigation details:
------------------
Implement non-execute huge pages in EPT.
This patch series clears the execute permission (bit 2) in the
EPT entries for large pages. When EPT violation is triggered by
guest instruction fetch, hypervisor converts the large page to
smaller 4 KB pages and restore the execute permission, and then
re-execute the guest instruction.
The current patch turns on the mitigation by default.
The follow-up patches will conditionally turn on/off the feature
per processor model.
[1] Refer to erratum KBL002 in "7th Generation Intel Processor
Family and 8th Generation Intel Processor Family for U Quad Core
Platforms Specification Update"
https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/7th-gen-core-family-spec-update.pdf
[2] Refer to erratum SKL002 in "6th Generation Intel Processor
Family Specification Update"
https://www.intel.com/content/www/us/en/products/docs/processors/core/desktop-6th-gen-core-family-spec-update.html
Tracked-On: #4120
Signed-off-by: Binbin Wu <binbin.wu@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@intel.com>
EPT tables are shared by MMU and IOMMU.
Some IOMMUs don't support page-walk coherency, the cpu cache of EPT entires
should be flushed to memory after modifications, so that the modifications
are visible to the IOMMUs.
This patch adds a new interface to flush the cache of modified EPT entires.
There are different implementations for EPT/PPT entries:
- For PPT, there is no need to flush the cpu cache after update.
- For EPT, need to call iommu_flush_cache to make the modifications visible
to IOMMUs.
Tracked-On: #4120
Signed-off-by: Binbin Wu <binbin.wu@intel.com>
Reviewed-by: Anthony Xu <anthony.xu@intel.com>
Under sharing mode, VM0 is identical with SOS VM. But the coupling of
SOS VM and VM 0 is not friendly for partition mode.
This patch is a pure term change of vm0 to sos VM, it does not change
any code logic or senmantic.
Tracked-On: #2291
Signed-off-by: Victor Sun <victor.sun@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Identifier reuse may arise confusion. So should minimize the case of it
as much as possible. This patch is try to do this except the PCI related
module.
Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
The previous would reserve memory for trusty in SOS kernel. Howerer,
there would no available 16 MB continue memory any more after a long time.
This result in allocating memory for trusty failed. This patch will reserve
memory for trusty in ACRN hypervisor in which case the memory allocation
for trusty will never fail.
Tracked-On: #1942
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
For data structure types "struct vm", its name is identical
with variable name in the same scope. This is a MISRA C violation.
Naming convention rule:If the data structure type is used by multi
modules, its corresponding logic resource is exposed to external
components (such as SOS, UOS), and its name meaning is simplistic
(such as vcpu, vm), its name needs prefix "acrn_".
The following udpates are made:
struct vm *vm-->struct acrn_vm *vm
Tracked-On: #861
Signed-off-by: Xiangyang Wu <xiangyang.wu@linux.intel.com>
In the C99 standard, the order of evaluation associated with multiple #,
multiple ## or a mix of # and ## preprocessor operator is unspecifie.
So it is unsafe to use multiple # or ## in a macro.
Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Normal world would also setup 511 GB gpa EPT mapping when initialize.
So we couldn't know which the world is from the gpa. But trusty is so
special for that we know where it would get a pml4_page or pdpt_page.
As a result, we could simpler this by just return the pml4_page or
pdpt_page to it when it needs.
Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Replace dynamic memory allocation in memory management with static memory allocation.
Since the static memory allocation can guarantee the allocation never failed, so
split_large_page and construct_pgentry don't need to return a errno any more.
Besides, the destroy_ept don't need to free page any more. Instead, it would memset
the eptp to 0 to make sure we can't walk this paging table again.
Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Add static paging table allocation API for EPT.
Note: must configure SOS/UOS_REAM_SIZE exactly as the platform.
Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Add static paging table allocation API for hypervisor.
Note: must configure PLATFORM_RAM_SIZE and PLATFORM_MMIO_SIZE exactly as the platform.
Rename RAM_START/RAM_SIZE to HV_RAM_START/HV_RAM_SIZE for HV.
Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
