[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH v2 01/27] target/riscv: Don't set write permissions on dirty PTEs
From: |
Alistair Francis |
Subject: |
[PATCH v2 01/27] target/riscv: Don't set write permissions on dirty PTEs |
Date: |
Fri, 25 Oct 2019 16:23:10 -0700 |
Setting write permission on dirty PTEs results in userspace inside a
Hypervisor guest (VU) becoming corrupted. This appears to be because it
ends up with write permission in the second stage translation in cases
where we aren't doing a store.
Signed-off-by: Alistair Francis <address@hidden>
Reviewed-by: Bin Meng <address@hidden>
---
target/riscv/cpu_helper.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 0e1a4d91fc..31f553efb9 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -344,10 +344,8 @@ restart:
if ((pte & PTE_X)) {
*prot |= PAGE_EXEC;
}
- /* add write permission on stores or if the page is already dirty,
- so that we TLB miss on later writes to update the dirty bit */
- if ((pte & PTE_W) &&
- (access_type == MMU_DATA_STORE || (pte & PTE_D))) {
+ /* add write permission on stores */
+ if ((pte & PTE_W) && (access_type == MMU_DATA_STORE)) {
*prot |= PAGE_WRITE;
}
return TRANSLATE_SUCCESS;
--
2.23.0
- [PATCH v2 00/27] Add RISC-V Hypervisor Extension v0.4, Alistair Francis, 2019/10/25
- [PATCH v2 01/27] target/riscv: Don't set write permissions on dirty PTEs,
Alistair Francis <=
- [PATCH v2 02/27] target/riscv: Add the Hypervisor extension, Alistair Francis, 2019/10/25
- [PATCH v2 03/27] target/riscv: Add the virtulisation mode, Alistair Francis, 2019/10/25
- [PATCH v2 04/27] target/riscv: Add the force HS exception mode, Alistair Francis, 2019/10/25
- [PATCH v2 08/27] target/riscv: Dump Hypervisor registers if enabled, Alistair Francis, 2019/10/25
- [PATCH v2 06/27] target/riscv: Add the Hypervisor CSRs to CPUState, Alistair Francis, 2019/10/25
- [PATCH v2 07/27] target/riscv: Print priv and virt in disas log, Alistair Francis, 2019/10/25
- [PATCH v2 05/27] target/riscv: Fix CSR perm checking for HS mode, Alistair Francis, 2019/10/25
- [PATCH v2 10/27] target/riscv: Add Hypervisor virtual CSRs accesses, Alistair Francis, 2019/10/25
- [PATCH v2 09/27] target/riscv: Add Hypervisor CSR access functions, Alistair Francis, 2019/10/25
- [PATCH v2 11/27] target/riscv: Convert mie and mstatus to pointers, Alistair Francis, 2019/10/25