mirror of
https://github.com/torvalds/linux.git
synced 2024-12-24 11:51:27 +00:00
5c40130801
On CPUs that support S2FWB (Armv8.4+), KVM configures the stage 2 page tables to override the memory attributes of memory accesses, regardless of the stage 1 page table configurations, and also when the stage 1 MMU is turned off. This results in all memory accesses to RAM being cacheable, including during early boot of the guest. On CPUs without this feature, memory accesses were non-cacheable during boot until the guest turned on the stage 1 MMU, and we had to detect when the guest turned on the MMU, such that we could invalidate all cache entries and ensure a consistent view of memory with the MMU turned on. When the guest turned on the caches, we would call stage2_flush_vm() from kvm_toggle_cache(). However, stage2_flush_vm() walks all the stage 2 tables, and calls __kvm_flush-dcache_pte, which on a system with S2FWB does ... absolutely nothing. We can avoid that whole song and dance, and simply not set TVM when creating a VM on a system that has S2FWB. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20191028130541.30536-1-christoffer.dall@arm.com |
||
---|---|---|
.. | ||
alpha | ||
arc | ||
arm | ||
arm64 | ||
c6x | ||
csky | ||
h8300 | ||
hexagon | ||
ia64 | ||
m68k | ||
microblaze | ||
mips | ||
nds32 | ||
nios2 | ||
openrisc | ||
parisc | ||
powerpc | ||
riscv | ||
s390 | ||
sh | ||
sparc | ||
um | ||
unicore32 | ||
x86 | ||
xtensa | ||
.gitignore | ||
Kconfig |