KVM: x86: Add support for "protected VMs" that can utilize private memory

Add a new x86 VM type, KVM_X86_SW_PROTECTED_VM, to serve as a development
and testing vehicle for Confidential (CoCo) VMs, and potentially to even
become a "real" product in the distant future, e.g. a la pKVM.

The private memory support in KVM x86 is aimed at AMD's SEV-SNP and
Intel's TDX, but those technologies are extremely complex (understatement),
difficult to debug, don't support running as nested guests, and require
hardware that's isn't universally accessible.  I.e. relying SEV-SNP or TDX
for maintaining guest private memory isn't a realistic option.

At the very least, KVM_X86_SW_PROTECTED_VM will enable a variety of
selftests for guest_memfd and private memory support without requiring
unique hardware.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20231027182217.3615211-24-seanjc@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

This commit is contained in:

Sean Christopherson

2023-10-27 11:22:05 -07:00

committed by

Paolo Bonzini

parent eed52e434b

commit 89ea60c2c7

8 changed files with 78 additions and 7 deletions

									
										arch/x86/include/uapi/asm/kvm.h
									
		+3
		
												View File
												
				@@ -562,4 +562,7 @@ struct kvm_pmu_event_filter {

				/* x86-specific KVM_EXIT_HYPERCALL flags. */

				#define KVM_EXIT_HYPERCALL_LONG_MODE	BIT(0)

				#define KVM_X86_DEFAULT_VM	0

				#define KVM_X86_SW_PROTECTED_VM	1

				#endif /* _ASM_X86_KVM_H */