tree 0e19144e59f5b06978b0e31c076897f0f9ebf5a8
parent a0aa6db7ce72a08703774107185e639e73e7754c
author Michael Roth <michael.roth@amd.com> 1717067799 -0500
committer Paolo Bonzini <pbonzini@redhat.com> 1717578066 +0200

hw/i386/sev: Use guest_memfd for legacy ROMs

Current SNP guest kernels will attempt to access these regions with
with C-bit set, so guest_memfd is needed to handle that. Otherwise,
kvm_convert_memory() will fail when the guest kernel tries to access it
and QEMU attempts to call KVM_SET_MEMORY_ATTRIBUTES to set these ranges
to private.

Whether guests should actually try to access ROM regions in this way (or
need to deal with legacy ROM regions at all), is a separate issue to be
addressed on kernel side, but current SNP guest kernels will exhibit
this behavior and so this handling is needed to allow QEMU to continue
running existing SNP guest kernels.

Signed-off-by: Michael Roth <michael.roth@amd.com>
[pankaj: Added sev_snp_enabled() check]
Signed-off-by: Pankaj Gupta <pankaj.gupta@amd.com>
Message-ID: <20240530111643.1091816-28-pankaj.gupta@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>