[PATCH AUTOSEL 4.19 34/87] MIPS: kvm: Use vm_get_page_prot to get protection bits

From: Sasha Levin
Date: Tue Dec 22 2020 - 21:50:09 EST


From: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>

[ Upstream commit 411406a8c758d9ad6f908fab3a6cf1d3d89e1d08 ]

MIPS protection bits are setup during runtime so using defines like
PAGE_SHARED ignores this runtime changes. Using vm_get_page_prot
to get correct page protection fixes this.

Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/mips/kvm/mmu.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index 098a7afd4d384..5631d6aee1a70 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -1099,6 +1099,7 @@ int kvm_mips_handle_commpage_tlb_fault(unsigned long badvaddr,
{
kvm_pfn_t pfn;
pte_t *ptep;
+ pgprot_t prot;

ptep = kvm_trap_emul_pte_for_gva(vcpu, badvaddr);
if (!ptep) {
@@ -1108,7 +1109,8 @@ int kvm_mips_handle_commpage_tlb_fault(unsigned long badvaddr,

pfn = PFN_DOWN(virt_to_phys(vcpu->arch.kseg0_commpage));
/* Also set valid and dirty, so refill handler doesn't have to */
- *ptep = pte_mkyoung(pte_mkdirty(pfn_pte(pfn, PAGE_SHARED)));
+ prot = vm_get_page_prot(VM_READ|VM_WRITE|VM_SHARED);
+ *ptep = pte_mkyoung(pte_mkdirty(pfn_pte(pfn, prot)));

/* Invalidate this entry in the TLB, guest kernel ASID only */
kvm_mips_host_tlb_inv(vcpu, badvaddr, false, true);
--
2.27.0