LoongArch: KVM: Clear LLBCTL if secondary mmu mapping is changed

Browse source

LLBCTL is a separated guest CSR register from host, host exception ERET
instruction will clear the host LLBCTL CSR register, and guest exception
will clear the guest LLBCTL CSR register.

VCPU0 atomic64_fetch_add_unless     VCPU1 atomic64_fetch_add_unless
     ll.d    %[p],  %[c]
     beq     %[p],  %[u], 1f

Here secondary mmu mapping is changed, host hpa page is replaced with a
new page. And VCPU1 will execute atomic instruction on the new page.

                                       ll.d    %[p],  %[c]
                                       beq     %[p],  %[u], 1f
                                       add.d   %[rc], %[p], %[a]
                                       sc.d    %[rc], %[c]
     add.d   %[rc], %[p], %[a]
     sc.d    %[rc], %[c]

LLBCTL is set on VCPU0 and it represents the memory is not modified by
other VCPUs, sc.d will modify the memory directly.

So clear WCLLB of the guest LLBCTL register when mapping is the changed.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

...

This commit is contained in:

Bibo Mao 2025-01-13 21:37:17 +08:00 • committed by Huacai Chen

parent 5bc55a333a

commit 4d38d0416e

1 changed files with 18 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

18

arch/loongarch/kvm/main.c

View file