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[PATCH v2] target/ppc: fix Hash64 MMU update of PTE bit R

Leandro Lupori posted 1 patch 2 years, 5 months ago
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git fetch https://github.com/patchew-project/qemu tags/patchew/20211125183322.47230-1-leandro.lupori@eldorado.org.br
Maintainers: Daniel Henrique Barboza <danielhb413@gmail.com>, David Gibson <david@gibson.dropbear.id.au>, Greg Kurz <groug@kaod.org>, "Cédric Le Goater" <clg@kaod.org>
There is a newer version of this series
target/ppc/mmu-hash64.c | 2 +-
target/ppc/mmu-hash64.h | 3 +++
2 files changed, 4 insertions(+), 1 deletion(-)
[PATCH v2] target/ppc: fix Hash64 MMU update of PTE bit R
Posted by Leandro Lupori 2 years, 5 months ago 
When updating the R bit of a PTE, the Hash64 MMU was using a wrong byte
offset, causing the first byte of the adjacent PTE to be corrupted.
This caused a panic when booting FreeBSD, using the Hash MMU.

Fixes: a2dd4e83e76b ("ppc/hash64: Rework R and C bit updates")
Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>
---
Changes from v1:
- Add and use a new define for the byte offset of PTE bit R
---
 target/ppc/mmu-hash64.c | 2 +-
 target/ppc/mmu-hash64.h | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
index 19832c4b46..0968927744 100644
--- a/target/ppc/mmu-hash64.c
+++ b/target/ppc/mmu-hash64.c
@@ -786,7 +786,7 @@ static void ppc_hash64_set_dsi(CPUState *cs, int mmu_idx, uint64_t dar, uint64_t
 
 static void ppc_hash64_set_r(PowerPCCPU *cpu, hwaddr ptex, uint64_t pte1)
 {
-    hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + 16;
+    hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + HPTE64_R_R_BYTE_OFFSET;
 
     if (cpu->vhyp) {
         PPCVirtualHypervisorClass *vhc =
diff --git a/target/ppc/mmu-hash64.h b/target/ppc/mmu-hash64.h
index c5b2f97ff7..40bb901262 100644
--- a/target/ppc/mmu-hash64.h
+++ b/target/ppc/mmu-hash64.h
@@ -97,6 +97,9 @@ void ppc_hash64_finalize(PowerPCCPU *cpu);
 #define HPTE64_V_1TB_SEG        0x4000000000000000ULL
 #define HPTE64_V_VRMA_MASK      0x4001ffffff000000ULL
 
+/* PTE byte offsets */
+#define HPTE64_R_R_BYTE_OFFSET  14
+
 /* Format changes for ARCH v3 */
 #define HPTE64_V_COMMON_BITS    0x000fffffffffffffULL
 #define HPTE64_R_3_0_SSIZE_SHIFT 58
-- 
2.25.1
Re: [PATCH v2] target/ppc: fix Hash64 MMU update of PTE bit R
Posted by David Gibson 2 years, 5 months ago 
On Thu, Nov 25, 2021 at 03:33:22PM -0300, Leandro Lupori wrote:
> When updating the R bit of a PTE, the Hash64 MMU was using a wrong byte
> offset, causing the first byte of the adjacent PTE to be corrupted.
> This caused a panic when booting FreeBSD, using the Hash MMU.
> 
> Fixes: a2dd4e83e76b ("ppc/hash64: Rework R and C bit updates")
> Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>

If you're introducing the constant, it would make sense to also use it
in spapr_hpte_set_r().

> ---
> Changes from v1:
> - Add and use a new define for the byte offset of PTE bit R
> ---
>  target/ppc/mmu-hash64.c | 2 +-
>  target/ppc/mmu-hash64.h | 3 +++
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
> index 19832c4b46..0968927744 100644
> --- a/target/ppc/mmu-hash64.c
> +++ b/target/ppc/mmu-hash64.c
> @@ -786,7 +786,7 @@ static void ppc_hash64_set_dsi(CPUState *cs, int mmu_idx, uint64_t dar, uint64_t
>  
>  static void ppc_hash64_set_r(PowerPCCPU *cpu, hwaddr ptex, uint64_t pte1)
>  {
> -    hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + 16;
> +    hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + HPTE64_R_R_BYTE_OFFSET;
>  
>      if (cpu->vhyp) {
>          PPCVirtualHypervisorClass *vhc =
> diff --git a/target/ppc/mmu-hash64.h b/target/ppc/mmu-hash64.h
> index c5b2f97ff7..40bb901262 100644
> --- a/target/ppc/mmu-hash64.h
> +++ b/target/ppc/mmu-hash64.h
> @@ -97,6 +97,9 @@ void ppc_hash64_finalize(PowerPCCPU *cpu);
>  #define HPTE64_V_1TB_SEG        0x4000000000000000ULL
>  #define HPTE64_V_VRMA_MASK      0x4001ffffff000000ULL
>  
> +/* PTE byte offsets */
> +#define HPTE64_R_R_BYTE_OFFSET  14
> +
>  /* Format changes for ARCH v3 */
>  #define HPTE64_V_COMMON_BITS    0x000fffffffffffffULL
>  #define HPTE64_R_3_0_SSIZE_SHIFT 58

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson
Re: [PATCH v2] target/ppc: fix Hash64 MMU update of PTE bit R
Posted by Cédric Le Goater 2 years, 5 months ago 
Hello,

Curiously, I didn't get the v2 email.

On 11/26/21 02:13, David Gibson wrote:
> On Thu, Nov 25, 2021 at 03:33:22PM -0300, Leandro Lupori wrote:
>> When updating the R bit of a PTE, the Hash64 MMU was using a wrong byte
>> offset, causing the first byte of the adjacent PTE to be corrupted.
>> This caused a panic when booting FreeBSD, using the Hash MMU.
>>
>> Fixes: a2dd4e83e76b ("ppc/hash64: Rework R and C bit updates")
>> Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>
> 
> If you're introducing the constant, it would make sense to also use it
> in spapr_hpte_set_r().

I agree and please add one for the C bit also since it's the same
kind of twiddling.

Thanks,

C.


>> ---
>> Changes from v1:
>> - Add and use a new define for the byte offset of PTE bit R
>> ---
>>   target/ppc/mmu-hash64.c | 2 +-
>>   target/ppc/mmu-hash64.h | 3 +++
>>   2 files changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
>> index 19832c4b46..0968927744 100644
>> --- a/target/ppc/mmu-hash64.c
>> +++ b/target/ppc/mmu-hash64.c
>> @@ -786,7 +786,7 @@ static void ppc_hash64_set_dsi(CPUState *cs, int mmu_idx, uint64_t dar, uint64_t
>>   
>>   static void ppc_hash64_set_r(PowerPCCPU *cpu, hwaddr ptex, uint64_t pte1)
>>   {
>> -    hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + 16;
>> +    hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + HPTE64_R_R_BYTE_OFFSET;
>>   
>>       if (cpu->vhyp) {
>>           PPCVirtualHypervisorClass *vhc =
>> diff --git a/target/ppc/mmu-hash64.h b/target/ppc/mmu-hash64.h
>> index c5b2f97ff7..40bb901262 100644
>> --- a/target/ppc/mmu-hash64.h
>> +++ b/target/ppc/mmu-hash64.h
>> @@ -97,6 +97,9 @@ void ppc_hash64_finalize(PowerPCCPU *cpu);
>>   #define HPTE64_V_1TB_SEG        0x4000000000000000ULL
>>   #define HPTE64_V_VRMA_MASK      0x4001ffffff000000ULL
>>   
>> +/* PTE byte offsets */
>> +#define HPTE64_R_R_BYTE_OFFSET  14>> +
>>   /* Format changes for ARCH v3 */
>>   #define HPTE64_V_COMMON_BITS    0x000fffffffffffffULL
>>   #define HPTE64_R_3_0_SSIZE_SHIFT 58
>
Re: [PATCH v2] target/ppc: fix Hash64 MMU update of PTE bit R
Posted by Leandro Lupori 2 years, 5 months ago 
On 26/11/2021 06:18, Cédric Le Goater wrote:
> 
> Hello,
> 
> Curiously, I didn't get the v2 email.
> 

I've received an e-mail from postmaster, saying that delivery to 
recipients @kaod.org have been delayed, but I don't know why.
Re: [PATCH v2] target/ppc: fix Hash64 MMU update of PTE bit R
Posted by Daniel Henrique Barboza 2 years, 5 months ago 

On 11/25/21 15:33, Leandro Lupori wrote:
> When updating the R bit of a PTE, the Hash64 MMU was using a wrong byte
> offset, causing the first byte of the adjacent PTE to be corrupted.
> This caused a panic when booting FreeBSD, using the Hash MMU.
> 
> Fixes: a2dd4e83e76b ("ppc/hash64: Rework R and C bit updates")
> Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>
> ---

Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>

> Changes from v1:
> - Add and use a new define for the byte offset of PTE bit R
> ---
>   target/ppc/mmu-hash64.c | 2 +-
>   target/ppc/mmu-hash64.h | 3 +++
>   2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
> index 19832c4b46..0968927744 100644
> --- a/target/ppc/mmu-hash64.c
> +++ b/target/ppc/mmu-hash64.c
> @@ -786,7 +786,7 @@ static void ppc_hash64_set_dsi(CPUState *cs, int mmu_idx, uint64_t dar, uint64_t
>   
>   static void ppc_hash64_set_r(PowerPCCPU *cpu, hwaddr ptex, uint64_t pte1)
>   {
> -    hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + 16;
> +    hwaddr base, offset = ptex * HASH_PTE_SIZE_64 + HPTE64_R_R_BYTE_OFFSET;
>   
>       if (cpu->vhyp) {
>           PPCVirtualHypervisorClass *vhc =
> diff --git a/target/ppc/mmu-hash64.h b/target/ppc/mmu-hash64.h
> index c5b2f97ff7..40bb901262 100644
> --- a/target/ppc/mmu-hash64.h
> +++ b/target/ppc/mmu-hash64.h
> @@ -97,6 +97,9 @@ void ppc_hash64_finalize(PowerPCCPU *cpu);
>   #define HPTE64_V_1TB_SEG        0x4000000000000000ULL
>   #define HPTE64_V_VRMA_MASK      0x4001ffffff000000ULL
>   
> +/* PTE byte offsets */
> +#define HPTE64_R_R_BYTE_OFFSET  14
> +
>   /* Format changes for ARCH v3 */
>   #define HPTE64_V_COMMON_BITS    0x000fffffffffffffULL
>   #define HPTE64_R_3_0_SSIZE_SHIFT 58
>

Patchew 2.1-devel-0870f84

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