Re: [PATCH v2] hw/cxl/device: Add Flex Bus Port DVSEC

[Ira Weiny]

On Thu, Dec 15, 2022 at 05:16:33PM +0000, Jonathan Cameron wrote:
> On Wed, 14 Dec 2022 12:54:11 -0800
> Ira Weiny <ira.weiny@intel.com> wrote:
> 
> > The Flex Bus Port DVSEC was missing on type 3 devices which was blocking
> > RAS checks.[1]
> > 
> > Add the Flex Bus Port DVSEC to type 3 devices as per CXL 3.0 8.2.1.3.
> > 
> > [1] 
> > https://lore.kernel.org/linux-cxl/167096738875.2861540.11815053323626849940.stgit@djiang5-desk3.ch.intel.com/
> > 
> > Cc: Dave Jiang <dave.jiang@intel.com>
> > Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Cc: Ben Widawsky <bwidawsk@kernel.org>
> > Cc: qemu-devel@nongnu.org
> > Cc: linux-cxl@vger.kernel.org
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> Looks good to me.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> As Michael wasn't cc'd on patch posting, so might not get this directly I'll 
> add
> it to the front of the series adding the RAS event emulation on basis that's 
> the
> first time we'll see a failure in Linux (I think?)

Ah thanks!

Sorry, I thought you were the 'maintainer' of the CXL stuff for qemu.

> 
> Michael, if you want to pick this up directly that's great too!

Should I send directly to Michael in future?

> 
> As a side note the WTF? is because we made up a hardware related time delay
> number having no idea whatsoever on what a realistic value was. Cut and paste
> from the instances of this structure in the root port and the switch ports.
> 

Yep I just followed that based off the other code.

Ira

> Jonathan
> 
> 
> 
> > ---
> > Changes in v2:
> >         Jonathan                                                            
> >                 type 3 device does not support CACHE                        
> >                 Comment the 68B bit                                         
> > 
> > - Link to v1: 
> > 20221213-ira-flexbus-port-v1-1-86afd4f30be6@intel.com">https://lore.kernel.org/r/20221213-ira-flexbus-port-v1-1-86afd4f30be6@intel.com
> > ---
> >  hw/mem/cxl_type3.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> > 
> > diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
> > index 0317bd96a6fb..e6beac143fc1 100644
> > --- a/hw/mem/cxl_type3.c
> > +++ b/hw/mem/cxl_type3.c
> > @@ -416,6 +416,17 @@ static void build_dvsecs(CXLType3Dev *ct3d)
> >      cxl_component_create_dvsec(cxl_cstate, CXL2_TYPE3_DEVICE,
> >                                 GPF_DEVICE_DVSEC_LENGTH, GPF_DEVICE_DVSEC,
> >                                 GPF_DEVICE_DVSEC_REVID, dvsec);
> > +
> > +    dvsec = (uint8_t *)&(CXLDVSECPortFlexBus){
> > +        .cap                     = 0x26, /* 68B, IO, Mem, non-MLD */
> > +        .ctrl                    = 0x02, /* IO always enabled */
> > +        .status                  = 0x26, /* same as capabilities */
> > +        .rcvd_mod_ts_data_phase1 = 0xef, /* WTF? */
> > +    };
> > +    cxl_component_create_dvsec(cxl_cstate, CXL2_TYPE3_DEVICE,
> > +                               PCIE_FLEXBUS_PORT_DVSEC_LENGTH_2_0,
> > +                               PCIE_FLEXBUS_PORT_DVSEC,
> > +                               PCIE_FLEXBUS_PORT_DVSEC_REVID_2_0, dvsec);
> >  }
> >  
> >  static void hdm_decoder_commit(CXLType3Dev *ct3d, int which)
> > 
> > ---
> > base-commit: e11b57108b0cb746bb9f3887054f34a2f818ed79
> > change-id: 20221213-ira-flexbus-port-ce526de8111d
> > 
> > Best regards,
>