[PATCH] target/i386: Fix test for paging enabled

[PATCH] target/i386: Fix test for paging enabled

[Richard Henderson]

If CR0.PG is unset, pg_mode will be zero, but that is not the
only condition for which pg_mode will be zero.  Restore the
correct test for paging enabled.

Fixes: 98281984a37 ("target/i386: Add MMU_PHYS_IDX and MMU_NESTED_IDX")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1269
Reported-by: Andreas Gustafsson <gson@gson.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/i386/tcg/sysemu/excp_helper.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/target/i386/tcg/sysemu/excp_helper.c b/target/i386/tcg/sysemu/excp_helper.c
index d51b5d7431..405a5d414a 100644
--- a/target/i386/tcg/sysemu/excp_helper.c
+++ b/target/i386/tcg/sysemu/excp_helper.c
@@ -553,12 +553,12 @@ static bool get_physical_address(CPUX86State *env, vaddr addr,
         break;
 
     default:
-        in.cr3 = env->cr[3];
-        in.mmu_idx = mmu_idx;
-        in.ptw_idx = use_stage2 ? MMU_NESTED_IDX : MMU_PHYS_IDX;
-        in.pg_mode = get_pg_mode(env);
+        if (likely(env->cr[0] & CR0_PG_MASK)) {
+            in.cr3 = env->cr[3];
+            in.mmu_idx = mmu_idx;
+            in.ptw_idx = use_stage2 ? MMU_NESTED_IDX : MMU_PHYS_IDX;
+            in.pg_mode = get_pg_mode(env);
 
-        if (likely(in.pg_mode)) {
             if (in.pg_mode & PG_MODE_LMA) {
                 /* test virtual address sign extension */
                 int shift = in.pg_mode & PG_MODE_LA57 ? 56 : 47;
-- 
2.34.1

Re: [PATCH] target/i386: Fix test for paging enabled

[Paolo Bonzini]

On 11/2/22 10:12, Richard Henderson wrote:
> If CR0.PG is unset, pg_mode will be zero, but that is not the
> only condition for which pg_mode will be zero.  Restore the
> correct test for paging enabled.
> 
> Fixes: 98281984a37 ("target/i386: Add MMU_PHYS_IDX and MMU_NESTED_IDX")
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1269
> Reported-by: Andreas Gustafsson <gson@gson.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/i386/tcg/sysemu/excp_helper.c | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/target/i386/tcg/sysemu/excp_helper.c b/target/i386/tcg/sysemu/excp_helper.c
> index d51b5d7431..405a5d414a 100644
> --- a/target/i386/tcg/sysemu/excp_helper.c
> +++ b/target/i386/tcg/sysemu/excp_helper.c
> @@ -553,12 +553,12 @@ static bool get_physical_address(CPUX86State *env, vaddr addr,
>           break;
>   
>       default:
> -        in.cr3 = env->cr[3];
> -        in.mmu_idx = mmu_idx;
> -        in.ptw_idx = use_stage2 ? MMU_NESTED_IDX : MMU_PHYS_IDX;
> -        in.pg_mode = get_pg_mode(env);
> +        if (likely(env->cr[0] & CR0_PG_MASK)) {
> +            in.cr3 = env->cr[3];
> +            in.mmu_idx = mmu_idx;
> +            in.ptw_idx = use_stage2 ? MMU_NESTED_IDX : MMU_PHYS_IDX;
> +            in.pg_mode = get_pg_mode(env);
>   
> -        if (likely(in.pg_mode)) {
>               if (in.pg_mode & PG_MODE_LMA) {
>                   /* test virtual address sign extension */
>                   int shift = in.pg_mode & PG_MODE_LA57 ? 56 : 47;

Queued, thanks.

Paolo