[PATCH] target/loongarch: Fix valid virtual address checking

[PATCH] target/loongarch: Fix valid virtual address checking

[Bibo Mao]

On LoongArch64 system, the high 32 bit of 64 bit virtual address should be
0x00000[0-7]yyy or 0xffff8yyy. The bit from 47 to 63 should be all 0 or
all 1.

Function get_physical_address() only checks bit 48 to 63, there will be
problem with the following test case. On physical machine, there is bus
error report and program exits abnormally. However on qemu TCG system
emulation mode, the program runs normally. The virtual address
0xffff000000000000ULL + addr and addr are treated the same on TLB entry
checking. This patch fixes this issue.

void main()
{
        void *addr, *addr1;
        int val;

        addr = malloc(100);
        *(int *)addr = 1;
        addr1 = 0xffff000000000000ULL + addr;
        val = *(int *)addr1;
        printf("val %d \n", val);
}

Cc: qemu-stable@nongnu.org
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
 target/loongarch/cpu_helper.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/loongarch/cpu_helper.c b/target/loongarch/cpu_helper.c
index e172b11ce1..b5f732f15b 100644
--- a/target/loongarch/cpu_helper.c
+++ b/target/loongarch/cpu_helper.c
@@ -196,8 +196,8 @@ int get_physical_address(CPULoongArchState *env, hwaddr *physical,
     }
 
     /* Check valid extension */
-    addr_high = sextract64(address, TARGET_VIRT_ADDR_SPACE_BITS, 16);
-    if (!(addr_high == 0 || addr_high == -1)) {
+    addr_high = (int64_t)address >> (TARGET_VIRT_ADDR_SPACE_BITS - 1);
+    if (!(addr_high == 0 || addr_high == -1ULL)) {
         return TLBRET_BADADDR;
     }
 

base-commit: 9a4e273ddec3927920c5958d2226c6b38b543336
-- 
2.39.3

Re: [PATCH] target/loongarch: Fix valid virtual address checking

[gaosong]

在 2025/7/14 上午9:54, Bibo Mao 写道:
> On LoongArch64 system, the high 32 bit of 64 bit virtual address should be
> 0x00000[0-7]yyy or 0xffff8yyy. The bit from 47 to 63 should be all 0 or
> all 1.
>
> Function get_physical_address() only checks bit 48 to 63, there will be
> problem with the following test case. On physical machine, there is bus
> error report and program exits abnormally. However on qemu TCG system
> emulation mode, the program runs normally. The virtual address
> 0xffff000000000000ULL + addr and addr are treated the same on TLB entry
> checking. This patch fixes this issue.
>
> void main()
> {
>          void *addr, *addr1;
>          int val;
>
>          addr = malloc(100);
>          *(int *)addr = 1;
>          addr1 = 0xffff000000000000ULL + addr;
>          val = *(int *)addr1;
>          printf("val %d \n", val);
> }
>
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
> ---
>   target/loongarch/cpu_helper.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
Acked-by: Song Gao <gaosong@loongson.cn>

thanks.
Song Gao
> diff --git a/target/loongarch/cpu_helper.c b/target/loongarch/cpu_helper.c
> index e172b11ce1..b5f732f15b 100644
> --- a/target/loongarch/cpu_helper.c
> +++ b/target/loongarch/cpu_helper.c
> @@ -196,8 +196,8 @@ int get_physical_address(CPULoongArchState *env, hwaddr *physical,
>       }
>   
>       /* Check valid extension */
> -    addr_high = sextract64(address, TARGET_VIRT_ADDR_SPACE_BITS, 16);
> -    if (!(addr_high == 0 || addr_high == -1)) {
> +    addr_high = (int64_t)address >> (TARGET_VIRT_ADDR_SPACE_BITS - 1);
> +    if (!(addr_high == 0 || addr_high == -1ULL)) {
>           return TLBRET_BADADDR;
>       }
>   
>
> base-commit: 9a4e273ddec3927920c5958d2226c6b38b543336

Re: [PATCH] target/loongarch: Fix valid virtual address checking

[gaosong]

在 2025/7/14 上午9:54, Bibo Mao 写道:
> On LoongArch64 system, the high 32 bit of 64 bit virtual address should be
> 0x00000[0-7]yyy or 0xffff8yyy. The bit from 47 to 63 should be all 0 or
> all 1.
>
> Function get_physical_address() only checks bit 48 to 63, there will be
> problem with the following test case. On physical machine, there is bus
> error report and program exits abnormally. However on qemu TCG system
> emulation mode, the program runs normally. The virtual address
> 0xffff000000000000ULL + addr and addr are treated the same on TLB entry
> checking. This patch fixes this issue.
>
> void main()
> {
>          void *addr, *addr1;
>          int val;
>
>          addr = malloc(100);
>          *(int *)addr = 1;
>          addr1 = 0xffff000000000000ULL + addr;
>          val = *(int *)addr1;
>          printf("val %d \n", val);
> }
>
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
> ---
>   target/loongarch/cpu_helper.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
Reviewed-by: Song Gao <gaosong@loongson.cn>

Thanks.
Song Gao
> diff --git a/target/loongarch/cpu_helper.c b/target/loongarch/cpu_helper.c
> index e172b11ce1..b5f732f15b 100644
> --- a/target/loongarch/cpu_helper.c
> +++ b/target/loongarch/cpu_helper.c
> @@ -196,8 +196,8 @@ int get_physical_address(CPULoongArchState *env, hwaddr *physical,
>       }
>   
>       /* Check valid extension */
> -    addr_high = sextract64(address, TARGET_VIRT_ADDR_SPACE_BITS, 16);
> -    if (!(addr_high == 0 || addr_high == -1)) {
> +    addr_high = (int64_t)address >> (TARGET_VIRT_ADDR_SPACE_BITS - 1);
> +    if (!(addr_high == 0 || addr_high == -1ULL)) {
>           return TLBRET_BADADDR;
>       }
>   
>
> base-commit: 9a4e273ddec3927920c5958d2226c6b38b543336