> How can I test this? Can I test it with virtio-pmem device? Correct. Assuming the CoCo guest accesses some virtio-pmem device in devdax mode, mmapping() this virtio-pmem device's memory region results in the guest and host reading the same (plaintext) values from the region.
> > Thanks, > Pankaj > > > > Signed-off-by: Kevin Loughlin <kevinlough...@google.co > --- > > drivers/dax/device.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/dax/device.c b/drivers/dax/device.c > > index 2051e4f73c8a..a284442d7ecc 100644 > > --- a/drivers/dax/device.c > > +++ b/drivers/dax/device.c > > @@ -11,6 +11,7 @@ > > #include <linux/fs.h> > > #include <linux/mm.h> > > #include <linux/mman.h> > > +#include <linux/cc_platform.h> > > #include "dax-private.h" > > #include "bus.h" > > > > @@ -303,6 +304,8 @@ static int dax_mmap(struct file *filp, struct > > vm_area_struct *vma) > > > > vma->vm_ops = &dax_vm_ops; > > vm_flags_set(vma, VM_HUGEPAGE); > > + if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) > > + vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); > > return 0; > > } > > >
