Commit 6d415778 authored by Adrian Hunter's avatar Adrian Hunter Committed by Paolo Bonzini
Browse files

KVM: TDX: Disable support for TSX and WAITPKG 



Support for restoring IA32_TSX_CTRL MSR and IA32_UMWAIT_CONTROL MSR is not
yet implemented, so disable support for TSX and WAITPKG for now.  Clear the
associated CPUID bits returned by KVM_TDX_CAPABILITIES, and return an error
if those bits are set in KVM_TDX_INIT_VM.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Message-ID: <20250129095902.16391-11-adrian.hunter@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e0b4f31a

arch/x86/kvm/vmx/tdx.c

+43 −0
Original line number Diff line number Diff line
@@ -107,6 +107,44 @@ static u32 tdx_set_guest_phys_addr_bits(const u32 eax, int addr_bits) 
	return (eax & ~GENMASK(23, 16)) | (addr_bits & 0xff) << 16;

}



#define TDX_FEATURE_TSX (__feature_bit(X86_FEATURE_HLE) | __feature_bit(X86_FEATURE_RTM))



static bool has_tsx(const struct kvm_cpuid_entry2 *entry)

{

	return entry->function == 7 && entry->index == 0 &&

	       (entry->ebx & TDX_FEATURE_TSX);

}



static void clear_tsx(struct kvm_cpuid_entry2 *entry)

{

	entry->ebx &= ~TDX_FEATURE_TSX;

}



static bool has_waitpkg(const struct kvm_cpuid_entry2 *entry)

{

	return entry->function == 7 && entry->index == 0 &&

	       (entry->ecx & __feature_bit(X86_FEATURE_WAITPKG));

}



static void clear_waitpkg(struct kvm_cpuid_entry2 *entry)

{

	entry->ecx &= ~__feature_bit(X86_FEATURE_WAITPKG);

}



static void tdx_clear_unsupported_cpuid(struct kvm_cpuid_entry2 *entry)

{

	if (has_tsx(entry))

		clear_tsx(entry);



	if (has_waitpkg(entry))

		clear_waitpkg(entry);

}



static bool tdx_unsupported_cpuid(const struct kvm_cpuid_entry2 *entry)

{

	return has_tsx(entry) || has_waitpkg(entry);

}



#define KVM_TDX_CPUID_NO_SUBLEAF	((__u32)-1)



static void td_init_cpuid_entry2(struct kvm_cpuid_entry2 *entry, unsigned char idx)
@@ -130,6 +168,8 @@ static void td_init_cpuid_entry2(struct kvm_cpuid_entry2 *entry, unsigned char i 
	 */

	if (entry->function == 0x80000008)

		entry->eax = tdx_set_guest_phys_addr_bits(entry->eax, 0xff);



	tdx_clear_unsupported_cpuid(entry);

}



static int init_kvm_tdx_caps(const struct tdx_sys_info_td_conf *td_conf,
@@ -1244,6 +1284,9 @@ static int setup_tdparams_cpuids(struct kvm_cpuid2 *cpuid, 
		if (!entry)

			continue;



		if (tdx_unsupported_cpuid(entry))

			return -EINVAL;



		copy_cnt++;



		value = &td_params->cpuid_values[i];