Commit e0fbb3bb authored by Isaku Yamahata's avatar Isaku Yamahata Committed by Paolo Bonzini
Browse files

KVM: TDX: Set gfn_direct_bits to shared bit 



Make the direct root handle memslot GFNs at an alias with the TDX shared
bit set.

For TDX shared memory, the memslot GFNs need to be mapped at an alias with
the shared bit set. These shared mappings will be mapped on the KVM MMU's
"direct" root. The direct root has it's mappings shifted by applying
"gfn_direct_bits" as a mask. The concept of "GPAW" (guest physical address
width) determines the location of the shared bit. So set gfn_direct_bits
based on this, to map shared memory at the proper GPA.

Signed-off-by: default avatarIsaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: default avatarRick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: default avatarRick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: default avatarYan Zhao <yan.y.zhao@intel.com>
Signed-off-by: default avatarYan Zhao <yan.y.zhao@intel.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241112073613.22100-1-yan.y.zhao@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 87e3f45e

arch/x86/kvm/vmx/tdx.c

+5 −0
Original line number Diff line number Diff line
@@ -1051,6 +1051,11 @@ static int tdx_td_init(struct kvm *kvm, struct kvm_tdx_cmd *cmd) 
	kvm_tdx->attributes = td_params->attributes;

	kvm_tdx->xfam = td_params->xfam;



	if (td_params->config_flags & TDX_CONFIG_FLAGS_MAX_GPAW)

		kvm->arch.gfn_direct_bits = TDX_SHARED_BIT_PWL_5;

	else

		kvm->arch.gfn_direct_bits = TDX_SHARED_BIT_PWL_4;



	kvm_tdx->state = TD_STATE_INITIALIZED;

out:

	/* kfree() accepts NULL. */