diff mbox series

[v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave ways

Message ID 20240407030642.24861-1-yaoxt.fnst@fujitsu.com (mailing list archive)
State New, archived
Headers show
Series [v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave ways | expand

Commit Message

Xingtao Yao (Fujitsu) April 7, 2024, 3:06 a.m. UTC 
Since the kernel does not check the interleave capability, a
3-way, 6-way, 12-way or 16-way region can be create normally.

Applications can access the memory of 16-way region normally because
qemu can convert hpa to dpa correctly for the power of 2 interleave
ways, after kernel implementing the check, this kind of region will
not be created any more.

For non power of 2 interleave ways, applications could not access the
memory normally and may occur some unexpected behaviors, such as
segmentation fault.

So implements this feature is needed.

Link: https://lore.kernel.org/linux-cxl/3e84b919-7631-d1db-3e1d-33000f3f3868@fujitsu.com/
Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
---
 hw/mem/cxl_type3.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

Comments

shiju.jose--- via April 24, 2024, 1:36 a.m. UTC | #1 
ping.

> -----Original Message-----
> From: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> Sent: Sunday, April 7, 2024 11:07 AM
> To: jonathan.cameron@huawei.com; fan.ni@samsung.com
> Cc: qemu-devel@nongnu.org; Yao, Xingtao/姚 幸涛 <yaoxt.fnst@fujitsu.com>
> Subject: [PATCH v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave ways
> 
> Since the kernel does not check the interleave capability, a
> 3-way, 6-way, 12-way or 16-way region can be create normally.
> 
> Applications can access the memory of 16-way region normally because
> qemu can convert hpa to dpa correctly for the power of 2 interleave
> ways, after kernel implementing the check, this kind of region will
> not be created any more.
> 
> For non power of 2 interleave ways, applications could not access the
> memory normally and may occur some unexpected behaviors, such as
> segmentation fault.
> 
> So implements this feature is needed.
> 
> Link:
> https://lore.kernel.org/linux-cxl/3e84b919-7631-d1db-3e1d-33000f3f3868@fujits
> u.com/
> Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> ---
>  hw/mem/cxl_type3.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
> index b0a7e9f11b..d6ef784e96 100644
> --- a/hw/mem/cxl_type3.c
> +++ b/hw/mem/cxl_type3.c
> @@ -805,10 +805,17 @@ static bool cxl_type3_dpa(CXLType3Dev *ct3d, hwaddr
> host_addr, uint64_t *dpa)
>              continue;
>          }
> 
> -        *dpa = dpa_base +
> -            ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> -             ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) & hpa_offset)
> -              >> iw));
> +        if (iw < 8) {
> +            *dpa = dpa_base +
> +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> +                 ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) & hpa_offset)
> +                  >> iw));
> +        } else {
> +            *dpa = dpa_base +
> +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> +                 ((((MAKE_64BIT_MASK(ig + iw, 64 - ig - iw) & hpa_offset)
> +                   >> (ig + iw)) / 3) << (ig + 8)));
> +        }
> 
>          return true;
>      }
> @@ -906,6 +913,9 @@ static void ct3d_reset(DeviceState *dev)
>      uint32_t *write_msk = ct3d->cxl_cstate.crb.cache_mem_regs_write_mask;
> 
>      cxl_component_register_init_common(reg_state, write_msk,
> CXL2_TYPE3_DEVICE);
> +    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY,
> 3_6_12_WAY, 1);
> +    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY,
> 16_WAY, 1);
> +
>      cxl_device_register_init_t3(ct3d);
> 
>      /*
> --
> 2.37.3
Jonathan Cameron April 30, 2024, 2:43 p.m. UTC | #2 
On Wed, 24 Apr 2024 01:36:56 +0000
"Xingtao Yao (Fujitsu)" <yaoxt.fnst@fujitsu.com> wrote:

> ping.
> 
> > -----Original Message-----
> > From: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> > Sent: Sunday, April 7, 2024 11:07 AM
> > To: jonathan.cameron@huawei.com; fan.ni@samsung.com
> > Cc: qemu-devel@nongnu.org; Yao, Xingtao/姚 幸涛 <yaoxt.fnst@fujitsu.com>
> > Subject: [PATCH v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave ways
> > 
> > Since the kernel does not check the interleave capability, a
> > 3-way, 6-way, 12-way or 16-way region can be create normally.
> > 
> > Applications can access the memory of 16-way region normally because
> > qemu can convert hpa to dpa correctly for the power of 2 interleave
> > ways, after kernel implementing the check, this kind of region will
> > not be created any more.
> > 
> > For non power of 2 interleave ways, applications could not access the
> > memory normally and may occur some unexpected behaviors, such as
> > segmentation fault.
> > 
> > So implements this feature is needed.
> > 
> > Link:
> > https://lore.kernel.org/linux-cxl/3e84b919-7631-d1db-3e1d-33000f3f3868@fujits
> > u.com/
> > Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> > ---
> >  hw/mem/cxl_type3.c | 18 ++++++++++++++----
> >  1 file changed, 14 insertions(+), 4 deletions(-)
> > 
> > diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
> > index b0a7e9f11b..d6ef784e96 100644
> > --- a/hw/mem/cxl_type3.c
> > +++ b/hw/mem/cxl_type3.c
> > @@ -805,10 +805,17 @@ static bool cxl_type3_dpa(CXLType3Dev *ct3d, hwaddr
> > host_addr, uint64_t *dpa)
> >              continue;
> >          }
> > 
> > -        *dpa = dpa_base +
> > -            ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > -             ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) & hpa_offset)  
> > -              >> iw));  
> > +        if (iw < 8) {
> > +            *dpa = dpa_base +
> > +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > +                 ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) & hpa_offset)
> > +                  >> iw));
> > +        } else {
> > +            *dpa = dpa_base +
> > +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > +                 ((((MAKE_64BIT_MASK(ig + iw, 64 - ig - iw) & hpa_offset)
> > +                   >> (ig + iw)) / 3) << (ig + 8)));
> > +        }
> > 
> >          return true;
> >      }
> > @@ -906,6 +913,9 @@ static void ct3d_reset(DeviceState *dev)
> >      uint32_t *write_msk = ct3d->cxl_cstate.crb.cache_mem_regs_write_mask;
> > 
> >      cxl_component_register_init_common(reg_state, write_msk,
> > CXL2_TYPE3_DEVICE);
> > +    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY,
> > 3_6_12_WAY, 1);
> > +    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY,
> > 16_WAY, 1);
> > +

Why here rather than in hdm_reg_init_common()?
It's constant data and is currently being set to 0 in there.

> >      cxl_device_register_init_t3(ct3d);
> > 
> >      /*
> > --
> > 2.37.3  
>
shiju.jose--- via May 7, 2024, 12:22 a.m. UTC | #3 
> -----Original Message-----
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Sent: Tuesday, April 30, 2024 10:43 PM
> To: Yao, Xingtao/姚 幸涛 <yaoxt.fnst@fujitsu.com>
> Cc: fan.ni@samsung.com; qemu-devel@nongnu.org
> Subject: Re: [PATCH v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave ways
> 
> On Wed, 24 Apr 2024 01:36:56 +0000
> "Xingtao Yao (Fujitsu)" <yaoxt.fnst@fujitsu.com> wrote:
> 
> > ping.
> >
> > > -----Original Message-----
> > > From: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> > > Sent: Sunday, April 7, 2024 11:07 AM
> > > To: jonathan.cameron@huawei.com; fan.ni@samsung.com
> > > Cc: qemu-devel@nongnu.org; Yao, Xingtao/姚 幸涛
> <yaoxt.fnst@fujitsu.com>
> > > Subject: [PATCH v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave ways
> > >
> > > Since the kernel does not check the interleave capability, a
> > > 3-way, 6-way, 12-way or 16-way region can be create normally.
> > >
> > > Applications can access the memory of 16-way region normally because
> > > qemu can convert hpa to dpa correctly for the power of 2 interleave
> > > ways, after kernel implementing the check, this kind of region will
> > > not be created any more.
> > >
> > > For non power of 2 interleave ways, applications could not access the
> > > memory normally and may occur some unexpected behaviors, such as
> > > segmentation fault.
> > >
> > > So implements this feature is needed.
> > >
> > > Link:
> > >
> https://lore.kernel.org/linux-cxl/3e84b919-7631-d1db-3e1d-33000f3f3868@fujits
> > > u.com/
> > > Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> > > ---
> > >  hw/mem/cxl_type3.c | 18 ++++++++++++++----
> > >  1 file changed, 14 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
> > > index b0a7e9f11b..d6ef784e96 100644
> > > --- a/hw/mem/cxl_type3.c
> > > +++ b/hw/mem/cxl_type3.c
> > > @@ -805,10 +805,17 @@ static bool cxl_type3_dpa(CXLType3Dev *ct3d,
> hwaddr
> > > host_addr, uint64_t *dpa)
> > >              continue;
> > >          }
> > >
> > > -        *dpa = dpa_base +
> > > -            ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > > -             ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) & hpa_offset)
> > > -              >> iw));
> > > +        if (iw < 8) {
> > > +            *dpa = dpa_base +
> > > +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > > +                 ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) &
> hpa_offset)
> > > +                  >> iw));
> > > +        } else {
> > > +            *dpa = dpa_base +
> > > +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > > +                 ((((MAKE_64BIT_MASK(ig + iw, 64 - ig - iw) & hpa_offset)
> > > +                   >> (ig + iw)) / 3) << (ig + 8)));
> > > +        }
> > >
> > >          return true;
> > >      }
> > > @@ -906,6 +913,9 @@ static void ct3d_reset(DeviceState *dev)
> > >      uint32_t *write_msk =
> ct3d->cxl_cstate.crb.cache_mem_regs_write_mask;
> > >
> > >      cxl_component_register_init_common(reg_state, write_msk,
> > > CXL2_TYPE3_DEVICE);
> > > +    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY,
> > > 3_6_12_WAY, 1);
> > > +    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY,
> > > 16_WAY, 1);
> > > +
> 
> Why here rather than in hdm_reg_init_common()?
> It's constant data and is currently being set to 0 in there.

according to the CXL specifications (8.2.4.20.1 CXL HDM Decoder Capability Register (Offset 00h)),
this feature is only applicable to cxl.mem, upstream switch port and CXL host bridges shall hardwrite
these bits to 0.

so I think it would be more appropriate to set these bits here.

> 
> > >      cxl_device_register_init_t3(ct3d);
> > >
> > >      /*
> > > --
> > > 2.37.3
> >
Jonathan Cameron May 7, 2024, 4:30 p.m. UTC | #4 
On Tue, 7 May 2024 00:22:00 +0000
"Xingtao Yao (Fujitsu)" <yaoxt.fnst@fujitsu.com> wrote:

> > -----Original Message-----
> > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Sent: Tuesday, April 30, 2024 10:43 PM
> > To: Yao, Xingtao/姚 幸涛 <yaoxt.fnst@fujitsu.com>
> > Cc: fan.ni@samsung.com; qemu-devel@nongnu.org
> > Subject: Re: [PATCH v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave ways
> > 
> > On Wed, 24 Apr 2024 01:36:56 +0000
> > "Xingtao Yao (Fujitsu)" <yaoxt.fnst@fujitsu.com> wrote:
> >   
> > > ping.
> > >  
> > > > -----Original Message-----
> > > > From: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> > > > Sent: Sunday, April 7, 2024 11:07 AM
> > > > To: jonathan.cameron@huawei.com; fan.ni@samsung.com
> > > > Cc: qemu-devel@nongnu.org; Yao, Xingtao/姚 幸涛  
> > <yaoxt.fnst@fujitsu.com>  
> > > > Subject: [PATCH v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave ways
> > > >
> > > > Since the kernel does not check the interleave capability, a
> > > > 3-way, 6-way, 12-way or 16-way region can be create normally.
> > > >
> > > > Applications can access the memory of 16-way region normally because
> > > > qemu can convert hpa to dpa correctly for the power of 2 interleave
> > > > ways, after kernel implementing the check, this kind of region will
> > > > not be created any more.
> > > >
> > > > For non power of 2 interleave ways, applications could not access the
> > > > memory normally and may occur some unexpected behaviors, such as
> > > > segmentation fault.
> > > >
> > > > So implements this feature is needed.
> > > >
> > > > Link:
> > > >  
> > https://lore.kernel.org/linux-cxl/3e84b919-7631-d1db-3e1d-33000f3f3868@fujits  
> > > > u.com/
> > > > Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> > > > ---
> > > >  hw/mem/cxl_type3.c | 18 ++++++++++++++----
> > > >  1 file changed, 14 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
> > > > index b0a7e9f11b..d6ef784e96 100644
> > > > --- a/hw/mem/cxl_type3.c
> > > > +++ b/hw/mem/cxl_type3.c
> > > > @@ -805,10 +805,17 @@ static bool cxl_type3_dpa(CXLType3Dev *ct3d,  
> > hwaddr  
> > > > host_addr, uint64_t *dpa)
> > > >              continue;
> > > >          }
> > > >
> > > > -        *dpa = dpa_base +
> > > > -            ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > > > -             ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) & hpa_offset)  
> > > > -              >> iw));  
> > > > +        if (iw < 8) {
> > > > +            *dpa = dpa_base +
> > > > +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > > > +                 ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) &  
> > hpa_offset)  
> > > > +                  >> iw));
> > > > +        } else {
> > > > +            *dpa = dpa_base +
> > > > +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > > > +                 ((((MAKE_64BIT_MASK(ig + iw, 64 - ig - iw) & hpa_offset)
> > > > +                   >> (ig + iw)) / 3) << (ig + 8)));
> > > > +        }
> > > >
> > > >          return true;
> > > >      }
> > > > @@ -906,6 +913,9 @@ static void ct3d_reset(DeviceState *dev)
> > > >      uint32_t *write_msk =  
> > ct3d->cxl_cstate.crb.cache_mem_regs_write_mask;  
> > > >
> > > >      cxl_component_register_init_common(reg_state, write_msk,
> > > > CXL2_TYPE3_DEVICE);
> > > > +    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY,
> > > > 3_6_12_WAY, 1);
> > > > +    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY,
> > > > 16_WAY, 1);
> > > > +  
> > 
> > Why here rather than in hdm_reg_init_common()?
> > It's constant data and is currently being set to 0 in there.  
> 
> according to the CXL specifications (8.2.4.20.1 CXL HDM Decoder Capability Register (Offset 00h)),
> this feature is only applicable to cxl.mem, upstream switch port and CXL host bridges shall hardwrite
> these bits to 0.
> 
> so I think it would be more appropriate to set these bits here.
I don't follow. hdm_init_common() (sorry wrong function name above)
has some type specific stuff already to show how this can be done.
I'd prefer to minimize what we set directly in the ct3d_reset() call
because it loses the connection to the rest of the register setup.

Jonathan



Jonathan


> 
> >   
> > > >      cxl_device_register_init_t3(ct3d);
> > > >
> > > >      /*
> > > > --
> > > > 2.37.3  
> > >  
>
shiju.jose--- via May 8, 2024, 12:52 a.m. UTC | #5 
> -----Original Message-----
> From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
> Sent: Wednesday, May 8, 2024 12:31 AM
> To: Yao, Xingtao/姚 幸涛 <yaoxt.fnst@fujitsu.com>
> Cc: fan.ni@samsung.com; qemu-devel@nongnu.org
> Subject: Re: [PATCH v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave ways
> 
> On Tue, 7 May 2024 00:22:00 +0000
> "Xingtao Yao (Fujitsu)" <yaoxt.fnst@fujitsu.com> wrote:
> 
> > > -----Original Message-----
> > > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > > Sent: Tuesday, April 30, 2024 10:43 PM
> > > To: Yao, Xingtao/姚 幸涛 <yaoxt.fnst@fujitsu.com>
> > > Cc: fan.ni@samsung.com; qemu-devel@nongnu.org
> > > Subject: Re: [PATCH v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave
> ways
> > >
> > > On Wed, 24 Apr 2024 01:36:56 +0000
> > > "Xingtao Yao (Fujitsu)" <yaoxt.fnst@fujitsu.com> wrote:
> > >
> > > > ping.
> > > >
> > > > > -----Original Message-----
> > > > > From: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> > > > > Sent: Sunday, April 7, 2024 11:07 AM
> > > > > To: jonathan.cameron@huawei.com; fan.ni@samsung.com
> > > > > Cc: qemu-devel@nongnu.org; Yao, Xingtao/姚 幸涛
> > > <yaoxt.fnst@fujitsu.com>
> > > > > Subject: [PATCH v2] mem/cxl_type3: support 3, 6, 12 and 16 interleave
> ways
> > > > >
> > > > > Since the kernel does not check the interleave capability, a
> > > > > 3-way, 6-way, 12-way or 16-way region can be create normally.
> > > > >
> > > > > Applications can access the memory of 16-way region normally because
> > > > > qemu can convert hpa to dpa correctly for the power of 2 interleave
> > > > > ways, after kernel implementing the check, this kind of region will
> > > > > not be created any more.
> > > > >
> > > > > For non power of 2 interleave ways, applications could not access the
> > > > > memory normally and may occur some unexpected behaviors, such as
> > > > > segmentation fault.
> > > > >
> > > > > So implements this feature is needed.
> > > > >
> > > > > Link:
> > > > >
> > >
> https://lore.kernel.org/linux-cxl/3e84b919-7631-d1db-3e1d-33000f3f3868@fujits
> > > > > u.com/
> > > > > Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
> > > > > ---
> > > > >  hw/mem/cxl_type3.c | 18 ++++++++++++++----
> > > > >  1 file changed, 14 insertions(+), 4 deletions(-)
> > > > >
> > > > > diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
> > > > > index b0a7e9f11b..d6ef784e96 100644
> > > > > --- a/hw/mem/cxl_type3.c
> > > > > +++ b/hw/mem/cxl_type3.c
> > > > > @@ -805,10 +805,17 @@ static bool cxl_type3_dpa(CXLType3Dev *ct3d,
> > > hwaddr
> > > > > host_addr, uint64_t *dpa)
> > > > >              continue;
> > > > >          }
> > > > >
> > > > > -        *dpa = dpa_base +
> > > > > -            ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > > > > -             ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) &
> hpa_offset)
> > > > > -              >> iw));
> > > > > +        if (iw < 8) {
> > > > > +            *dpa = dpa_base +
> > > > > +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > > > > +                 ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) &
> > > hpa_offset)
> > > > > +                  >> iw));
> > > > > +        } else {
> > > > > +            *dpa = dpa_base +
> > > > > +                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
> > > > > +                 ((((MAKE_64BIT_MASK(ig + iw, 64 - ig - iw) &
> hpa_offset)
> > > > > +                   >> (ig + iw)) / 3) << (ig + 8)));
> > > > > +        }
> > > > >
> > > > >          return true;
> > > > >      }
> > > > > @@ -906,6 +913,9 @@ static void ct3d_reset(DeviceState *dev)
> > > > >      uint32_t *write_msk =
> > > ct3d->cxl_cstate.crb.cache_mem_regs_write_mask;
> > > > >
> > > > >      cxl_component_register_init_common(reg_state, write_msk,
> > > > > CXL2_TYPE3_DEVICE);
> > > > > +    ARRAY_FIELD_DP32(reg_state,
> CXL_HDM_DECODER_CAPABILITY,
> > > > > 3_6_12_WAY, 1);
> > > > > +    ARRAY_FIELD_DP32(reg_state,
> CXL_HDM_DECODER_CAPABILITY,
> > > > > 16_WAY, 1);
> > > > > +
> > >
> > > Why here rather than in hdm_reg_init_common()?
> > > It's constant data and is currently being set to 0 in there.
> >
> > according to the CXL specifications (8.2.4.20.1 CXL HDM Decoder Capability
> Register (Offset 00h)),
> > this feature is only applicable to cxl.mem, upstream switch port and CXL host
> bridges shall hardwrite
> > these bits to 0.
> >
> > so I think it would be more appropriate to set these bits here.
> I don't follow. hdm_init_common() (sorry wrong function name above)
> has some type specific stuff already to show how this can be done.
> I'd prefer to minimize what we set directly in the ct3d_reset() call
> because it loses the connection to the rest of the register setup.
thanks, got it.
> 
> Jonathan
> 
> 
> 
> Jonathan
> 
> 
> >
> > >
> > > > >      cxl_device_register_init_t3(ct3d);
> > > > >
> > > > >      /*
> > > > > --
> > > > > 2.37.3
> > > >
> >
diff mbox series

Patch

diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index b0a7e9f11b..d6ef784e96 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -805,10 +805,17 @@  static bool cxl_type3_dpa(CXLType3Dev *ct3d, hwaddr host_addr, uint64_t *dpa)
             continue;
         }
 
-        *dpa = dpa_base +
-            ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
-             ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) & hpa_offset)
-              >> iw));
+        if (iw < 8) {
+            *dpa = dpa_base +
+                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
+                 ((MAKE_64BIT_MASK(8 + ig + iw, 64 - 8 - ig - iw) & hpa_offset)
+                  >> iw));
+        } else {
+            *dpa = dpa_base +
+                ((MAKE_64BIT_MASK(0, 8 + ig) & hpa_offset) |
+                 ((((MAKE_64BIT_MASK(ig + iw, 64 - ig - iw) & hpa_offset)
+                   >> (ig + iw)) / 3) << (ig + 8)));
+        }
 
         return true;
     }
@@ -906,6 +913,9 @@  static void ct3d_reset(DeviceState *dev)
     uint32_t *write_msk = ct3d->cxl_cstate.crb.cache_mem_regs_write_mask;
 
     cxl_component_register_init_common(reg_state, write_msk, CXL2_TYPE3_DEVICE);
+    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY, 3_6_12_WAY, 1);
+    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY, 16_WAY, 1);
+
     cxl_device_register_init_t3(ct3d);
 
     /*