diff mbox series

[v2,08/24] KVM: TDX: Set gfn_direct_bits to shared bit

Message ID 20241112073613.22100-1-yan.y.zhao@intel.com (mailing list archive)
State New
Headers show
Series TDX MMU Part 2 | expand

Commit Message

Yan Zhao Nov. 12, 2024, 7:36 a.m. UTC 
From: Isaku Yamahata <isaku.yamahata@intel.com>

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: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
TDX MMU part 2 v2:
 - Added Paolo's rb
 - Use TDX 1.5 naming of config_flags instead of exec_controls (Xiaoyao)
 - Use macro TDX_SHARED_BITS_PWL_5 and TDX_SHARED_BITS_PWL_4 for
   gfn_direct_bits. (Yan)

TDX MMU part 2 v1:
 - Move setting of gfn_direct_bits to separate patch (Yan)
---
 arch/x86/kvm/vmx/tdx.c | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 785ee9f95504..38369cafc175 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1041,6 +1041,11 @@  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. */