diff options
| author | Oliver Upton <[email protected]> | 2024-03-07 00:56:01 +0000 |
|---|---|---|
| committer | Oliver Upton <[email protected]> | 2024-03-07 00:56:01 +0000 |
| commit | 9bd8d7df1971c2ebdcaf4526cf7a3f4ea38d0ede (patch) | |
| tree | 1a773f15a68befda40169b1a8432742909d2b3f3 /include | |
| parent | 8dbc41105e96641e9c1569f512d19f0046a02463 (diff) | |
| parent | a39d3a966a090989b89c0287a67cd98c85ae2f52 (diff) | |
Merge branch kvm-arm64/vfio-normal-nc into kvmarm/next
* kvm-arm64/vfio-normal-nc:
: Normal-NC support for vfio-pci @ stage-2, courtesy of Ankit Agrawal
:
: KVM's policy to date has been that any and all MMIO mapping at stage-2
: is treated as Device-nGnRE. This is primarily done due to concerns of
: the guest triggering uncontainable failures in the system if they manage
: to tickle the device / memory system the wrong way, though this is
: unnecessarily restrictive for devices that can be reasoned as 'safe'.
:
: Unsurprisingly, the Device-* mapping can really hurt the performance of
: assigned devices that can handle Gathering, and can be an outright
: correctness issue if the guest driver does unaligned accesses.
:
: Rather than opening the floodgates to the full ecosystem of devices that
: can be exposed to VMs, take the conservative approach and allow PCI
: devices to be mapped as Normal-NC since it has been determined to be
: 'safe'.
vfio: Convey kvm that the vfio-pci device is wc safe
KVM: arm64: Set io memory s2 pte as normalnc for vfio pci device
mm: Introduce new flag to indicate wc safe
KVM: arm64: Introduce new flag for non-cacheable IO memory
Signed-off-by: Oliver Upton <[email protected]>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mm.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index f5a97dec5169..59576e56c58b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -391,6 +391,20 @@ extern unsigned int kobjsize(const void *objp); # define VM_UFFD_MINOR VM_NONE #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ +/* + * This flag is used to connect VFIO to arch specific KVM code. It + * indicates that the memory under this VMA is safe for use with any + * non-cachable memory type inside KVM. Some VFIO devices, on some + * platforms, are thought to be unsafe and can cause machine crashes + * if KVM does not lock down the memory type. + */ +#ifdef CONFIG_64BIT +#define VM_ALLOW_ANY_UNCACHED_BIT 39 +#define VM_ALLOW_ANY_UNCACHED BIT(VM_ALLOW_ANY_UNCACHED_BIT) +#else +#define VM_ALLOW_ANY_UNCACHED VM_NONE +#endif + /* Bits set in the VMA until the stack is in its final location */ #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY) |