Merge: Backport TDX suport to RHEL 10.1 + assorted minor KVM bugfixes

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1212

This patch series backports TDX suport to RHEL 10.1

JIRA: https://issues.redhat.com/browse/RHEL-47242

Sanity tested on AMD and Intel machine.

Omitted-fix: c126b46 ("Avoid calling kvm_is_mmio_pfn() when kvm_x86_ops.get_mt_mask is NULL")

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>

Approved-by: David Arcari <darcari@redhat.com>
Approved-by: Paolo Bonzini <bonzini@gnu.org>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Julio Faracco <jfaracco@redhat.com>

Author: jcfaracco

Documentation/virt/kvm/api.rst

@@ -1411,6 +1411,9 @@ the memory region are automatically reflected into the guest.  For example, an
 mmap() that affects the region will be made visible immediately.  Another
 example is madvise(MADV_DROP).
 
+For TDX guest, deleting/moving memory region loses guest memory contents.
+Read only region isn't supported.  Only as-id 0 is supported.
+
 Note: On arm64, a write generated by the page-table walker (to update
 the Access and Dirty flags, for example) never results in a
 KVM_EXIT_MMIO exit when the slot has the KVM_MEM_READONLY flag. This
@@ -2005,6 +2008,13 @@ If the KVM_CAP_VM_TSC_CONTROL capability is advertised, this can also
 be used as a vm ioctl to set the initial tsc frequency of subsequently
 created vCPUs.
 
+For TSC protected Confidential Computing (CoCo) VMs where TSC frequency
+is configured once at VM scope and remains unchanged during VM's
+lifetime, the vm ioctl should be used to configure the TSC frequency
+and the vcpu ioctl is not supported.
+
+Example of such CoCo VMs: TDX guests.
+
 4.56 KVM_GET_TSC_KHZ
 --------------------
 
@@ -4780,17 +4790,19 @@ H_GET_CPU_CHARACTERISTICS hypercall.
 
 :Capability: basic
 :Architectures: x86
-:Type: vm
+:Type: vm ioctl, vcpu ioctl
 :Parameters: an opaque platform specific structure (in/out)
 :Returns: 0 on success; -1 on error
 
 If the platform supports creating encrypted VMs then this ioctl can be used
 for issuing platform-specific memory encryption commands to manage those
 encrypted VMs.
 
-Currently, this ioctl is used for issuing Secure Encrypted Virtualization
-(SEV) commands on AMD Processors. The SEV commands are defined in
-Documentation/virt/kvm/x86/amd-memory-encryption.rst.
+Currently, this ioctl is used for issuing both Secure Encrypted Virtualization
+(SEV) commands on AMD Processors and Trusted Domain Extensions (TDX) commands
+on Intel Processors.  The detailed commands are defined in
+Documentation/virt/kvm/x86/amd-memory-encryption.rst and
+Documentation/virt/kvm/x86/intel-tdx.rst.
 
 4.111 KVM_MEMORY_ENCRYPT_REG_REGION
 -----------------------------------
@@ -6640,7 +6652,8 @@ to the byte array.
 .. note::
 
       For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, KVM_EXIT_XEN,
-      KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding
+      KVM_EXIT_EPR, KVM_EXIT_HYPERCALL, KVM_EXIT_TDX,
+      KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding
       operations are complete (and guest state is consistent) only after userspace
       has re-entered the kernel with KVM_RUN.  The kernel side will first finish
       incomplete operations and then check for pending signals.
@@ -6839,6 +6852,7 @@ should put the acknowledged interrupt vector into the 'epr' field.
   #define KVM_SYSTEM_EVENT_WAKEUP         4
   #define KVM_SYSTEM_EVENT_SUSPEND        5
   #define KVM_SYSTEM_EVENT_SEV_TERM       6
+  #define KVM_SYSTEM_EVENT_TDX_FATAL      7
 			__u32 type;
                         __u32 ndata;
                         __u64 data[16];
@@ -6865,6 +6879,11 @@ Valid values for 'type' are:
    reset/shutdown of the VM.
  - KVM_SYSTEM_EVENT_SEV_TERM -- an AMD SEV guest requested termination.
    The guest physical address of the guest's GHCB is stored in `data[0]`.
+ - KVM_SYSTEM_EVENT_TDX_FATAL -- a TDX guest reported a fatal error state.
+   KVM doesn't do any parsing or conversion, it just dumps 16 general-purpose
+   registers to userspace, in ascending order of the 4-bit indices for x86-64
+   general-purpose registers in instruction encoding, as defined in the Intel
+   SDM.
  - KVM_SYSTEM_EVENT_WAKEUP -- the exiting vCPU is in a suspended state and
    KVM has recognized a wakeup event. Userspace may honor this event by
    marking the exiting vCPU as runnable, or deny it and call KVM_RUN again.
@@ -7163,6 +7182,69 @@ The valid value for 'flags' is:
   - KVM_NOTIFY_CONTEXT_INVALID -- the VM context is corrupted and not valid
     in VMCS. It would run into unknown result if resume the target VM.
 
+::
+
+		/* KVM_EXIT_TDX */
+		struct {
+			__u64 flags;
+			__u64 nr;
+			union {
+				struct {
+					u64 ret;
+					u64 data[5];
+				} unknown;
+				struct {
+					u64 ret;
+					u64 gpa;
+					u64 size;
+				} get_quote;
+				struct {
+					u64 ret;
+					u64 leaf;
+					u64 r11, r12, r13, r14;
+				} get_tdvmcall_info;
+				struct {
+					u64 ret;
+					u64 vector;
+				} setup_event_notify;
+			};
+		} tdx;
+
+Process a TDVMCALL from the guest.  KVM forwards select TDVMCALL based
+on the Guest-Hypervisor Communication Interface (GHCI) specification;
+KVM bridges these requests to the userspace VMM with minimal changes,
+placing the inputs in the union and copying them back to the guest
+on re-entry.
+
+Flags are currently always zero, whereas ``nr`` contains the TDVMCALL
+number from register R11.  The remaining field of the union provide the
+inputs and outputs of the TDVMCALL.  Currently the following values of
+``nr`` are defined:
+
+ * ``TDVMCALL_GET_QUOTE``: the guest has requested to generate a TD-Quote
+   signed by a service hosting TD-Quoting Enclave operating on the host.
+   Parameters and return value are in the ``get_quote`` field of the union.
+   The ``gpa`` field and ``size`` specify the guest physical address
+   (without the shared bit set) and the size of a shared-memory buffer, in
+   which the TDX guest passes a TD Report.  The ``ret`` field represents
+   the return value of the GetQuote request.  When the request has been
+   queued successfully, the TDX guest can poll the status field in the
+   shared-memory area to check whether the Quote generation is completed or
+   not. When completed, the generated Quote is returned via the same buffer.
+
+ * ``TDVMCALL_GET_TD_VM_CALL_INFO``: the guest has requested the support
+   status of TDVMCALLs.  The output values for the given leaf should be
+   placed in fields from ``r11`` to ``r14`` of the ``get_tdvmcall_info``
+   field of the union.
+
+ * ``TDVMCALL_SETUP_EVENT_NOTIFY_INTERRUPT``: the guest has requested to
+   set up a notification interrupt for vector ``vector``.
+
+KVM may add support for more values in the future that may cause a userspace
+exit, even without calls to ``KVM_ENABLE_CAP`` or similar.  In this case,
+it will enter with output fields already valid; in the common case, the
+``unknown.ret`` field of the union will be ``TDVMCALL_STATUS_SUBFUNC_UNSUPPORTED``.
+Userspace need not do anything if it does not wish to support a TDVMCALL.
 ::
 
 		/* Fix the size of the union. */
@@ -8206,6 +8288,28 @@ KVM_X86_QUIRK_STUFF_FEATURE_MSRS    By default, at vCPU creation, KVM sets the
                                     and 0x489), as KVM does now allow them to
                                     be set by userspace (KVM sets them based on
                                     guest CPUID, for safety purposes).
+
+KVM_X86_QUIRK_IGNORE_GUEST_PAT      By default, on Intel platforms, KVM ignores
+                                    guest PAT and forces the effective memory
+                                    type to WB in EPT.  The quirk is not available
+                                    on Intel platforms which are incapable of
+                                    safely honoring guest PAT (i.e., without CPU
+                                    self-snoop, KVM always ignores guest PAT and
+                                    forces effective memory type to WB).  It is
+                                    also ignored on AMD platforms or, on Intel,
+                                    when a VM has non-coherent DMA devices
+                                    assigned; KVM always honors guest PAT in
+                                    such case. The quirk is needed to avoid
+                                    slowdowns on certain Intel Xeon platforms
+                                    (e.g. ICX, SPR) where self-snoop feature is
+                                    supported but UC is slow enough to cause
+                                    issues with some older guests that use
+                                    UC instead of WC to map the video RAM.
+                                    Userspace can disable the quirk to honor
+                                    guest PAT if it knows that there is no such
+                                    guest software, for example if it does not
+                                    expose a bochs graphics device (which is
+                                    known to have had a buggy driver).
 =================================== ============================================
 
 7.32 KVM_CAP_MAX_VCPU_ID

Documentation/virt/kvm/x86/index.rst

@@ -11,6 +11,7 @@ KVM for x86 systems
    cpuid
    errata
    hypercalls
+   intel-tdx
    mmu
    msr
    nested-vmx