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[PATCH v2] hw/mem/cxl_type3: reset dvsecs in ct3d_reset()

Li Zhijian via posted 1 patch 3 weeks, 3 days ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20240409075846.85370-1-lizhijian@fujitsu.com
Maintainers: Jonathan Cameron <jonathan.cameron@huawei.com>, Fan Ni <fan.ni@samsung.com>
hw/mem/cxl_type3.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
[PATCH v2] hw/mem/cxl_type3: reset dvsecs in ct3d_reset()
Posted by Li Zhijian via 3 weeks, 3 days ago 
After the kernel commit
0cab68720598 ("cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window")
CXL type3 devices cannot be enabled again after the reboot because the
control register(see 8.1.3.2 in CXL specifiction 2.0 for more details) was
not reset.

These registers could be changed by the firmware or OS, let them have
their initial value in reboot so that the OS can read their clean status.

Fixes: e1706ea83da0 ("hw/cxl/device: Add a memory device (8.2.8.5)")
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
---
root_port, usp and dsp have the same issue, if this patch get approved,
I will send another patch to fix them later.

V2:
   Add fixes tag.
   Reset all dvsecs registers instead of CTRL only
---
 hw/mem/cxl_type3.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index b0a7e9f11b64..4f09d0b8fedc 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -30,6 +30,7 @@
 #include "hw/pci/msix.h"
 
 #define DWORD_BYTE 4
+#define CT3D_CAP_SN_OFFSET PCI_CONFIG_SPACE_SIZE
 
 /* Default CDAT entries for a memory region */
 enum {
@@ -284,6 +285,10 @@ static void build_dvsecs(CXLType3Dev *ct3d)
              range2_size_hi = 0, range2_size_lo = 0,
              range2_base_hi = 0, range2_base_lo = 0;
 
+    cxl_cstate->dvsec_offset = CT3D_CAP_SN_OFFSET;
+    if (ct3d->sn != UI64_NULL) {
+        cxl_cstate->dvsec_offset += PCI_EXT_CAP_DSN_SIZEOF;
+    }
     /*
      * Volatile memory is mapped as (0x0)
      * Persistent memory is mapped at (volatile->size)
@@ -664,10 +669,7 @@ static void ct3_realize(PCIDevice *pci_dev, Error **errp)
 
     pcie_endpoint_cap_init(pci_dev, 0x80);
     if (ct3d->sn != UI64_NULL) {
-        pcie_dev_ser_num_init(pci_dev, 0x100, ct3d->sn);
-        cxl_cstate->dvsec_offset = 0x100 + 0x0c;
-    } else {
-        cxl_cstate->dvsec_offset = 0x100;
+        pcie_dev_ser_num_init(pci_dev, CT3D_CAP_SN_OFFSET, ct3d->sn);
     }
 
     ct3d->cxl_cstate.pdev = pci_dev;
@@ -907,6 +909,7 @@ static void ct3d_reset(DeviceState *dev)
 
     cxl_component_register_init_common(reg_state, write_msk, CXL2_TYPE3_DEVICE);
     cxl_device_register_init_t3(ct3d);
+    build_dvsecs(ct3d);
 
     /*
      * Bring up an endpoint to target with MCTP over VDM.
-- 
2.29.2
Re: [PATCH v2] hw/mem/cxl_type3: reset dvsecs in ct3d_reset()
Posted by Jonathan Cameron via 3 weeks, 1 day ago 
On Tue,  9 Apr 2024 15:58:46 +0800
Li Zhijian <lizhijian@fujitsu.com> wrote:

> After the kernel commit
> 0cab68720598 ("cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window")
> CXL type3 devices cannot be enabled again after the reboot because the
> control register(see 8.1.3.2 in CXL specifiction 2.0 for more details) was
> not reset.
> 
> These registers could be changed by the firmware or OS, let them have
> their initial value in reboot so that the OS can read their clean status.
> 
> Fixes: e1706ea83da0 ("hw/cxl/device: Add a memory device (8.2.8.5)")
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Hi,

We need to have a close look at what this is actually doing before
considering applying it.  I don't have time to get that this week, but
hopefully will find some time later this month.

I don't want a partial fix for one particular case that causes
us potential trouble in others.

Jonathan

> ---
> root_port, usp and dsp have the same issue, if this patch get approved,
> I will send another patch to fix them later.
> 
> V2:
>    Add fixes tag.
>    Reset all dvsecs registers instead of CTRL only
> ---
>  hw/mem/cxl_type3.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
> index b0a7e9f11b64..4f09d0b8fedc 100644
> --- a/hw/mem/cxl_type3.c
> +++ b/hw/mem/cxl_type3.c
> @@ -30,6 +30,7 @@
>  #include "hw/pci/msix.h"
>  
>  #define DWORD_BYTE 4
> +#define CT3D_CAP_SN_OFFSET PCI_CONFIG_SPACE_SIZE
>  
>  /* Default CDAT entries for a memory region */
>  enum {
> @@ -284,6 +285,10 @@ static void build_dvsecs(CXLType3Dev *ct3d)
>               range2_size_hi = 0, range2_size_lo = 0,
>               range2_base_hi = 0, range2_base_lo = 0;
>  
> +    cxl_cstate->dvsec_offset = CT3D_CAP_SN_OFFSET;
> +    if (ct3d->sn != UI64_NULL) {
> +        cxl_cstate->dvsec_offset += PCI_EXT_CAP_DSN_SIZEOF;
> +    }
>      /*
>       * Volatile memory is mapped as (0x0)
>       * Persistent memory is mapped at (volatile->size)
> @@ -664,10 +669,7 @@ static void ct3_realize(PCIDevice *pci_dev, Error **errp)
>  
>      pcie_endpoint_cap_init(pci_dev, 0x80);
>      if (ct3d->sn != UI64_NULL) {
> -        pcie_dev_ser_num_init(pci_dev, 0x100, ct3d->sn);
> -        cxl_cstate->dvsec_offset = 0x100 + 0x0c;
> -    } else {
> -        cxl_cstate->dvsec_offset = 0x100;
> +        pcie_dev_ser_num_init(pci_dev, CT3D_CAP_SN_OFFSET, ct3d->sn);
>      }
>  
>      ct3d->cxl_cstate.pdev = pci_dev;
> @@ -907,6 +909,7 @@ static void ct3d_reset(DeviceState *dev)
>  
>      cxl_component_register_init_common(reg_state, write_msk, CXL2_TYPE3_DEVICE);
>      cxl_device_register_init_t3(ct3d);
> +    build_dvsecs(ct3d);
>  
>      /*
>       * Bring up an endpoint to target with MCTP over VDM.
Re: [PATCH v2] hw/mem/cxl_type3: reset dvsecs in ct3d_reset()
Posted by Zhijian Li (Fujitsu) via 1 week ago 
ping



On 11/04/2024 18:18, Jonathan Cameron wrote:
> On Tue,  9 Apr 2024 15:58:46 +0800
> Li Zhijian <lizhijian@fujitsu.com> wrote:
> 
>> After the kernel commit
>> 0cab68720598 ("cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window")
>> CXL type3 devices cannot be enabled again after the reboot because the
>> control register(see 8.1.3.2 in CXL specifiction 2.0 for more details) was
>> not reset.
>>
>> These registers could be changed by the firmware or OS, let them have
>> their initial value in reboot so that the OS can read their clean status.
>>
>> Fixes: e1706ea83da0 ("hw/cxl/device: Add a memory device (8.2.8.5)")
>> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
> Hi,
> 
> We need to have a close look at what this is actually doing before
> considering applying it.  I don't have time to get that this week, but
> hopefully will find some time later this month.
> 
> I don't want a partial fix for one particular case that causes
> us potential trouble in others.
> 
> Jonathan
> 
>> ---
>> root_port, usp and dsp have the same issue, if this patch get approved,
>> I will send another patch to fix them later.
>>
>> V2:
>>     Add fixes tag.
>>     Reset all dvsecs registers instead of CTRL only
>> ---
>>   hw/mem/cxl_type3.c | 11 +++++++----
>>   1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
>> index b0a7e9f11b64..4f09d0b8fedc 100644
>> --- a/hw/mem/cxl_type3.c
>> +++ b/hw/mem/cxl_type3.c
>> @@ -30,6 +30,7 @@
>>   #include "hw/pci/msix.h"
>>   
>>   #define DWORD_BYTE 4
>> +#define CT3D_CAP_SN_OFFSET PCI_CONFIG_SPACE_SIZE
>>   
>>   /* Default CDAT entries for a memory region */
>>   enum {
>> @@ -284,6 +285,10 @@ static void build_dvsecs(CXLType3Dev *ct3d)
>>                range2_size_hi = 0, range2_size_lo = 0,
>>                range2_base_hi = 0, range2_base_lo = 0;
>>   
>> +    cxl_cstate->dvsec_offset = CT3D_CAP_SN_OFFSET;
>> +    if (ct3d->sn != UI64_NULL) {
>> +        cxl_cstate->dvsec_offset += PCI_EXT_CAP_DSN_SIZEOF;
>> +    }
>>       /*
>>        * Volatile memory is mapped as (0x0)
>>        * Persistent memory is mapped at (volatile->size)
>> @@ -664,10 +669,7 @@ static void ct3_realize(PCIDevice *pci_dev, Error **errp)
>>   
>>       pcie_endpoint_cap_init(pci_dev, 0x80);
>>       if (ct3d->sn != UI64_NULL) {
>> -        pcie_dev_ser_num_init(pci_dev, 0x100, ct3d->sn);
>> -        cxl_cstate->dvsec_offset = 0x100 + 0x0c;
>> -    } else {
>> -        cxl_cstate->dvsec_offset = 0x100;
>> +        pcie_dev_ser_num_init(pci_dev, CT3D_CAP_SN_OFFSET, ct3d->sn);
>>       }
>>   
>>       ct3d->cxl_cstate.pdev = pci_dev;
>> @@ -907,6 +909,7 @@ static void ct3d_reset(DeviceState *dev)
>>   
>>       cxl_component_register_init_common(reg_state, write_msk, CXL2_TYPE3_DEVICE);
>>       cxl_device_register_init_t3(ct3d);
>> +    build_dvsecs(ct3d);
>>   
>>       /*
>>        * Bring up an endpoint to target with MCTP over VDM.
>

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