Re: [PATCH v2 1/2] tpm: CRB: Use ram_device for "tpm-crb-cmd" region

[Alex Williamson <alex.williamson@redhat.com>]

On Wed, 19 Jan 2022 23:46:19 +0100
Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:

> On 18/1/22 16:33, Eric Auger wrote:
> > Representing the CRB cmd/response buffer as a standard
> > RAM region causes some trouble when the device is used
> > with VFIO. Indeed VFIO attempts to DMA_MAP this region
> > as usual RAM but this latter does not have a valid page
> > size alignment causing such an error report:
> > "vfio_listener_region_add received unaligned region".
> > To allow VFIO to detect that failing dma mapping
> > this region is not an issue, let's use a ram_device
> > memory region type instead.
> > 
> > The change in meson.build is required to include the
> > cpu.h header.
> > 
> > Signed-off-by: Eric Auger <eric.auger@redhat.com>
> > Tested-by: Stefan Berger <stefanb@linux.ibm.com>
> > 
> > ---
> > 
> > v1 -> v2:
> > - Add tpm_crb_unrealize
> > ---
> >   hw/tpm/meson.build |  2 +-
> >   hw/tpm/tpm_crb.c   | 22 ++++++++++++++++++++--
> >   2 files changed, 21 insertions(+), 3 deletions(-)
> > 
> > diff --git a/hw/tpm/meson.build b/hw/tpm/meson.build
> > index 1c68d81d6a..3e74df945b 100644
> > --- a/hw/tpm/meson.build
> > +++ b/hw/tpm/meson.build
> > @@ -1,8 +1,8 @@
> >   softmmu_ss.add(when: 'CONFIG_TPM_TIS', if_true: files('tpm_tis_common.c'))
> >   softmmu_ss.add(when: 'CONFIG_TPM_TIS_ISA', if_true: files('tpm_tis_isa.c'))
> >   softmmu_ss.add(when: 'CONFIG_TPM_TIS_SYSBUS', if_true: files('tpm_tis_sysbus.c'))
> > -softmmu_ss.add(when: 'CONFIG_TPM_CRB', if_true: files('tpm_crb.c'))
> >   
> > +specific_ss.add(when: 'CONFIG_TPM_CRB', if_true: files('tpm_crb.c'))  
> 
> We don't need to make this file target-specific.
> 
> >   specific_ss.add(when: ['CONFIG_SOFTMMU', 'CONFIG_TPM_TIS'], if_true: files('tpm_ppi.c'))
> >   specific_ss.add(when: ['CONFIG_SOFTMMU', 'CONFIG_TPM_CRB'], if_true: files('tpm_ppi.c'))
> >   specific_ss.add(when: 'CONFIG_TPM_SPAPR', if_true: files('tpm_spapr.c'))
> > diff --git a/hw/tpm/tpm_crb.c b/hw/tpm/tpm_crb.c
> > index 58ebd1469c..6ec19a9911 100644
> > --- a/hw/tpm/tpm_crb.c
> > +++ b/hw/tpm/tpm_crb.c
> > @@ -25,6 +25,7 @@
> >   #include "sysemu/tpm_backend.h"
> >   #include "sysemu/tpm_util.h"
> >   #include "sysemu/reset.h"
> > +#include "cpu.h"
> >   #include "tpm_prop.h"
> >   #include "tpm_ppi.h"
> >   #include "trace.h"
> > @@ -43,6 +44,7 @@ struct CRBState {
> >   
> >       bool ppi_enabled;
> >       TPMPPI ppi;
> > +    uint8_t *crb_cmd_buf;
> >   };
> >   typedef struct CRBState CRBState;
> >   
> > @@ -291,10 +293,14 @@ static void tpm_crb_realize(DeviceState *dev, Error **errp)
> >           return;
> >       }
> >   
> > +    s->crb_cmd_buf = qemu_memalign(ç,
> > +                                HOST_PAGE_ALIGN(CRB_CTRL_CMD_SIZE));  
> 
> HOST_PAGE_ALIGN() and qemu_real_host_page_size() actually belong
> to "exec/cpu-common.h".
> 
> Alex, could you hold on a few days for this patch? I am going to send
> a cleanup series. Otherwise no worry, I will clean this on top too.

Sure.  Thanks,

Alex