238 Commits

Author SHA1 Message Date
Paolo Bonzini
9a78e15802 KVM: x86: allow KVM_REQ_GET_NESTED_STATE_PAGES outside guest mode for VMX
VMX also uses KVM_REQ_GET_NESTED_STATE_PAGES for the Hyper-V eVMCS,
which may need to be loaded outside guest mode.  Therefore we cannot
WARN in that case.

However, that part of nested_get_vmcs12_pages is _not_ needed at
vmentry time.  Split it out of KVM_REQ_GET_NESTED_STATE_PAGES handling,
so that both vmentry and migration (and in the latter case, independent
of is_guest_mode) do the parts that are needed.

Cc: <stable@vger.kernel.org> # 5.10.x: f2c7ef3ba: KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES
Cc: <stable@vger.kernel.org> # 5.10.x
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-25 18:54:09 -05:00
Sean Christopherson
250091409a KVM: SVM: Unconditionally sync GPRs to GHCB on VMRUN of SEV-ES guest
Drop the per-GPR dirty checks when synchronizing GPRs to the GHCB, the
GRPs' dirty bits are set from time zero and never cleared, i.e. will
always be seen as dirty.  The obvious alternative would be to clear
the dirty bits when appropriate, but removing the dirty checks is
desirable as it allows reverting GPR dirty+available tracking, which
adds overhead to all flavors of x86 VMs.

Note, unconditionally writing the GPRs in the GHCB is tacitly allowed
by the GHCB spec, which allows the hypervisor (or guest) to provide
unnecessary info; it's the guest's responsibility to consume only what
it needs (the hypervisor is untrusted after all).

  The guest and hypervisor can supply additional state if desired but
  must not rely on that additional state being provided.

Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Fixes: 291bd20d5d88 ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210122235049.3107620-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-25 18:52:09 -05:00
Lorenzo Brescia
d95df95106 kvm: tracing: Fix unmatched kvm_entry and kvm_exit events
On VMX, if we exit and then re-enter immediately without leaving
the vmx_vcpu_run() function, the kvm_entry event is not logged.
That means we will see one (or more) kvm_exit, without its (their)
corresponding kvm_entry, as shown here:

 CPU-1979 [002] 89.871187: kvm_entry: vcpu 1
 CPU-1979 [002] 89.871218: kvm_exit:  reason MSR_WRITE
 CPU-1979 [002] 89.871259: kvm_exit:  reason MSR_WRITE

It also seems possible for a kvm_entry event to be logged, but then
we leave vmx_vcpu_run() right away (if vmx->emulation_required is
true). In this case, we will have a spurious kvm_entry event in the
trace.

Fix these situations by moving trace_kvm_entry() inside vmx_vcpu_run()
(where trace_kvm_exit() already is).

A trace obtained with this patch applied looks like this:

 CPU-14295 [000] 8388.395387: kvm_entry: vcpu 0
 CPU-14295 [000] 8388.395392: kvm_exit:  reason MSR_WRITE
 CPU-14295 [000] 8388.395393: kvm_entry: vcpu 0
 CPU-14295 [000] 8388.395503: kvm_exit:  reason EXTERNAL_INTERRUPT

Of course, not calling trace_kvm_entry() in common x86 code any
longer means that we need to adjust the SVM side of things too.

Signed-off-by: Lorenzo Brescia <lorenzo.brescia@edu.unito.it>
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
Message-Id: <160873470698.11652.13483635328769030605.stgit@Wayrath>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-25 18:52:08 -05:00
Tom Lendacky
647daca25d KVM: SVM: Add support for booting APs in an SEV-ES guest
Typically under KVM, an AP is booted using the INIT-SIPI-SIPI sequence,
where the guest vCPU register state is updated and then the vCPU is VMRUN
to begin execution of the AP. For an SEV-ES guest, this won't work because
the guest register state is encrypted.

Following the GHCB specification, the hypervisor must not alter the guest
register state, so KVM must track an AP/vCPU boot. Should the guest want
to park the AP, it must use the AP Reset Hold exit event in place of, for
example, a HLT loop.

First AP boot (first INIT-SIPI-SIPI sequence):
  Execute the AP (vCPU) as it was initialized and measured by the SEV-ES
  support. It is up to the guest to transfer control of the AP to the
  proper location.

Subsequent AP boot:
  KVM will expect to receive an AP Reset Hold exit event indicating that
  the vCPU is being parked and will require an INIT-SIPI-SIPI sequence to
  awaken it. When the AP Reset Hold exit event is received, KVM will place
  the vCPU into a simulated HLT mode. Upon receiving the INIT-SIPI-SIPI
  sequence, KVM will make the vCPU runnable. It is again up to the guest
  to then transfer control of the AP to the proper location.

  To differentiate between an actual HLT and an AP Reset Hold, a new MP
  state is introduced, KVM_MP_STATE_AP_RESET_HOLD, which the vCPU is
  placed in upon receiving the AP Reset Hold exit event. Additionally, to
  communicate the AP Reset Hold exit event up to userspace (if needed), a
  new exit reason is introduced, KVM_EXIT_AP_RESET_HOLD.

A new x86 ops function is introduced, vcpu_deliver_sipi_vector, in order
to accomplish AP booting. For VMX, vcpu_deliver_sipi_vector is set to the
original SIPI delivery function, kvm_vcpu_deliver_sipi_vector(). SVM adds
a new function that, for non SEV-ES guests, invokes the original SIPI
delivery function, kvm_vcpu_deliver_sipi_vector(), but for SEV-ES guests,
implements the logic above.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <e8fbebe8eb161ceaabdad7c01a5859a78b424d5e.1609791600.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-07 18:11:37 -05:00
Maxim Levitsky
f2c7ef3ba9 KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES on nested vmexit
It is possible to exit the nested guest mode, entered by
svm_set_nested_state prior to first vm entry to it (e.g due to pending event)
if the nested run was not pending during the migration.

In this case we must not switch to the nested msr permission bitmap.
Also add a warning to catch similar cases in the future.

Fixes: a7d5c7ce41ac1 ("KVM: nSVM: delay MSR permission processing to first nested VM run")

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210107093854.882483-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-07 18:11:35 -05:00
Maxim Levitsky
56fe28de8c KVM: nSVM: mark vmcb as dirty when forcingly leaving the guest mode
We overwrite most of vmcb fields while doing so, so we must
mark it as dirty.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210107093854.882483-5-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-07 18:11:34 -05:00
Maxim Levitsky
81f76adad5 KVM: nSVM: correctly restore nested_run_pending on migration
The code to store it on the migration exists, but no code was restoring it.

One of the side effects of fixing this is that L1->L2 injected events
are no longer lost when migration happens with nested run pending.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210107093854.882483-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-07 18:11:33 -05:00
Uros Bizjak
52782d5b63 KVM/SVM: Remove leftover __svm_vcpu_run prototype from svm.c
Commit 16809ecdc1e8a moved __svm_vcpu_run the prototype to svm.h,
but forgot to remove the original from svm.c.

Fixes: 16809ecdc1e8a ("KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests")
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Message-Id: <20201220200339.65115-1-ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-07 18:07:28 -05:00
Nathan Chancellor
f65cf84ee7 KVM: SVM: Add register operand to vmsave call in sev_es_vcpu_load
When using LLVM's integrated assembler (LLVM_IAS=1) while building
x86_64_defconfig + CONFIG_KVM=y + CONFIG_KVM_AMD=y, the following build
error occurs:

 $ make LLVM=1 LLVM_IAS=1 arch/x86/kvm/svm/sev.o
 arch/x86/kvm/svm/sev.c:2004:15: error: too few operands for instruction
         asm volatile(__ex("vmsave") : : "a" (__sme_page_pa(sd->save_area)) : "memory");
                      ^
 arch/x86/kvm/svm/sev.c:28:17: note: expanded from macro '__ex'
 #define __ex(x) __kvm_handle_fault_on_reboot(x)
                 ^
 ./arch/x86/include/asm/kvm_host.h:1646:10: note: expanded from macro '__kvm_handle_fault_on_reboot'
         "666: \n\t"                                                     \
                 ^
 <inline asm>:2:2: note: instantiated into assembly here
         vmsave
         ^
 1 error generated.

This happens because LLVM currently does not support calling vmsave
without the fixed register operand (%rax for 64-bit and %eax for
32-bit). This will be fixed in LLVM 12 but the kernel currently supports
LLVM 10.0.1 and newer so this needs to be handled.

Add the proper register using the _ASM_AX macro, which matches the
vmsave call in vmenter.S.

Fixes: 861377730aa9 ("KVM: SVM: Provide support for SEV-ES vCPU loading")
Link: https://reviews.llvm.org/D93524
Link: https://github.com/ClangBuiltLinux/linux/issues/1216
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Message-Id: <20201219063711.3526947-1-natechancellor@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-07 18:07:27 -05:00
Paolo Bonzini
bc351f0726 Merge branch 'kvm-master' into kvm-next
Fixes to get_mmio_spte, destined to 5.10 stable branch.
2021-01-07 18:06:52 -05:00
Paolo Bonzini
d45f89f743 KVM: SVM: fix 32-bit compilation
VCPU_REGS_R8...VCPU_REGS_R15 are not defined on 32-bit x86,
so cull them from the synchronization of the VMSA.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-16 13:08:21 -05:00
Tom Lendacky
8640ca588b KVM: SVM: Add AP_JUMP_TABLE support in prep for AP booting
The GHCB specification requires the hypervisor to save the address of an
AP Jump Table so that, for example, vCPUs that have been parked by UEFI
can be started by the OS. Provide support for the AP Jump Table set/get
exit code.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 12:47:53 -05:00
Tom Lendacky
ad73109ae7 KVM: SVM: Provide support to launch and run an SEV-ES guest
An SEV-ES guest is started by invoking a new SEV initialization ioctl,
KVM_SEV_ES_INIT. This identifies the guest as an SEV-ES guest, which is
used to drive the appropriate ASID allocation, VMSA encryption, etc.

Before being able to run an SEV-ES vCPU, the vCPU VMSA must be encrypted
and measured. This is done using the LAUNCH_UPDATE_VMSA command after all
calls to LAUNCH_UPDATE_DATA have been performed, but before LAUNCH_MEASURE
has been performed. In order to establish the encrypted VMSA, the current
(traditional) VMSA and the GPRs are synced to the page that will hold the
encrypted VMSA and then LAUNCH_UPDATE_VMSA is invoked. The vCPU is then
marked as having protected guest state.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <e9643245adb809caf3a87c09997926d2f3d6ff41.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:21:00 -05:00
Tom Lendacky
16809ecdc1 KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests
The run sequence is different for an SEV-ES guest compared to a legacy or
even an SEV guest. The guest vCPU register state of an SEV-ES guest will
be restored on VMRUN and saved on VMEXIT. There is no need to restore the
guest registers directly and through VMLOAD before VMRUN and no need to
save the guest registers directly and through VMSAVE on VMEXIT.

Update the svm_vcpu_run() function to skip register state saving and
restoring and provide an alternative function for running an SEV-ES guest
in vmenter.S

Additionally, certain host state is restored across an SEV-ES VMRUN. As
a result certain register states are not required to be restored upon
VMEXIT (e.g. FS, GS, etc.), so only do that if the guest is not an SEV-ES
guest.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <fb1c66d32f2194e171b95fc1a8affd6d326e10c1.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:59 -05:00
Tom Lendacky
861377730a KVM: SVM: Provide support for SEV-ES vCPU loading
An SEV-ES vCPU requires additional VMCB vCPU load/put requirements. SEV-ES
hardware will restore certain registers on VMEXIT, but not save them on
VMRUN (see Table B-3 and Table B-4 of the AMD64 APM Volume 2), so make the
following changes:

General vCPU load changes:
  - During vCPU loading, perform a VMSAVE to the per-CPU SVM save area and
    save the current values of XCR0, XSS and PKRU to the per-CPU SVM save
    area as these registers will be restored on VMEXIT.

General vCPU put changes:
  - Do not attempt to restore registers that SEV-ES hardware has already
    restored on VMEXIT.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <019390e9cb5e93cd73014fa5a040c17d42588733.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:59 -05:00
Tom Lendacky
376c6d2850 KVM: SVM: Provide support for SEV-ES vCPU creation/loading
An SEV-ES vCPU requires additional VMCB initialization requirements for
vCPU creation and vCPU load/put requirements. This includes:

General VMCB initialization changes:
  - Set a VMCB control bit to enable SEV-ES support on the vCPU.
  - Set the VMCB encrypted VM save area address.
  - CRx registers are part of the encrypted register state and cannot be
    updated. Remove the CRx register read and write intercepts and replace
    them with CRx register write traps to track the CRx register values.
  - Certain MSR values are part of the encrypted register state and cannot
    be updated. Remove certain MSR intercepts (EFER, CR_PAT, etc.).
  - Remove the #GP intercept (no support for "enable_vmware_backdoor").
  - Remove the XSETBV intercept since the hypervisor cannot modify XCR0.

General vCPU creation changes:
  - Set the initial GHCB gpa value as per the GHCB specification.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <3a8aef366416eddd5556dfa3fdc212aafa1ad0a2.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:58 -05:00
Tom Lendacky
80675b3ad4 KVM: SVM: Update ASID allocation to support SEV-ES guests
SEV and SEV-ES guests each have dedicated ASID ranges. Update the ASID
allocation routine to return an ASID in the respective range.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <d7aed505e31e3954268b2015bb60a1486269c780.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:57 -05:00
Tom Lendacky
85ca8be938 KVM: SVM: Set the encryption mask for the SVM host save area
The SVM host save area is used to restore some host state on VMEXIT of an
SEV-ES guest. After allocating the save area, clear it and add the
encryption mask to the SVM host save area physical address that is
programmed into the VM_HSAVE_PA MSR.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <b77aa28af6d7f1a0cb545959e08d6dc75e0c3cba.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:57 -05:00
Tom Lendacky
4444dfe405 KVM: SVM: Add NMI support for an SEV-ES guest
The GHCB specification defines how NMIs are to be handled for an SEV-ES
guest. To detect the completion of an NMI the hypervisor must not
intercept the IRET instruction (because a #VC while running the NMI will
issue an IRET) and, instead, must receive an NMI Complete exit event from
the guest.

Update the KVM support for detecting the completion of NMIs in the guest
to follow the GHCB specification. When an SEV-ES guest is active, the
IRET instruction will no longer be intercepted. Now, when the NMI Complete
exit event is received, the iret_interception() function will be called
to simulate the completion of the NMI.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <5ea3dd69b8d4396cefdc9048ebc1ab7caa70a847.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:56 -05:00
Tom Lendacky
ed02b21309 KVM: SVM: Guest FPU state save/restore not needed for SEV-ES guest
The guest FPU state is automatically restored on VMRUN and saved on VMEXIT
by the hardware, so there is no reason to do this in KVM. Eliminate the
allocation of the guest_fpu save area and key off that to skip operations
related to the guest FPU state.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <173e429b4d0d962c6a443c4553ffdaf31b7665a4.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:56 -05:00
Tom Lendacky
5719455fbd KVM: SVM: Do not report support for SMM for an SEV-ES guest
SEV-ES guests do not currently support SMM. Update the has_emulated_msr()
kvm_x86_ops function to take a struct kvm parameter so that the capability
can be reported at a VM level.

Since this op is also called during KVM initialization and before a struct
kvm instance is available, comments will be added to each implementation
of has_emulated_msr() to indicate the kvm parameter can be null.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <75de5138e33b945d2fb17f81ae507bda381808e3.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:55 -05:00
Tom Lendacky
d1949b93c6 KVM: SVM: Add support for CR8 write traps for an SEV-ES guest
For SEV-ES guests, the interception of control register write access
is not recommended. Control register interception occurs prior to the
control register being modified and the hypervisor is unable to modify
the control register itself because the register is located in the
encrypted register state.

SEV-ES guests introduce new control register write traps. These traps
provide intercept support of a control register write after the control
register has been modified. The new control register value is provided in
the VMCB EXITINFO1 field, allowing the hypervisor to track the setting
of the guest control registers.

Add support to track the value of the guest CR8 register using the control
register write trap so that the hypervisor understands the guest operating
mode.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <5a01033f4c8b3106ca9374b7cadf8e33da852df1.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:54 -05:00
Tom Lendacky
5b51cb1316 KVM: SVM: Add support for CR4 write traps for an SEV-ES guest
For SEV-ES guests, the interception of control register write access
is not recommended. Control register interception occurs prior to the
control register being modified and the hypervisor is unable to modify
the control register itself because the register is located in the
encrypted register state.

SEV-ES guests introduce new control register write traps. These traps
provide intercept support of a control register write after the control
register has been modified. The new control register value is provided in
the VMCB EXITINFO1 field, allowing the hypervisor to track the setting
of the guest control registers.

Add support to track the value of the guest CR4 register using the control
register write trap so that the hypervisor understands the guest operating
mode.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <c3880bf2db8693aa26f648528fbc6e967ab46e25.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:53 -05:00
Tom Lendacky
f27ad38aac KVM: SVM: Add support for CR0 write traps for an SEV-ES guest
For SEV-ES guests, the interception of control register write access
is not recommended. Control register interception occurs prior to the
control register being modified and the hypervisor is unable to modify
the control register itself because the register is located in the
encrypted register state.

SEV-ES support introduces new control register write traps. These traps
provide intercept support of a control register write after the control
register has been modified. The new control register value is provided in
the VMCB EXITINFO1 field, allowing the hypervisor to track the setting
of the guest control registers.

Add support to track the value of the guest CR0 register using the control
register write trap so that the hypervisor understands the guest operating
mode.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <182c9baf99df7e40ad9617ff90b84542705ef0d7.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:52 -05:00
Tom Lendacky
2985afbcdb KVM: SVM: Add support for EFER write traps for an SEV-ES guest
For SEV-ES guests, the interception of EFER write access is not
recommended. EFER interception occurs prior to EFER being modified and
the hypervisor is unable to modify EFER itself because the register is
located in the encrypted register state.

SEV-ES support introduces a new EFER write trap. This trap provides
intercept support of an EFER write after it has been modified. The new
EFER value is provided in the VMCB EXITINFO1 field, allowing the
hypervisor to track the setting of the guest EFER.

Add support to track the value of the guest EFER value using the EFER
write trap so that the hypervisor understands the guest operating mode.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <8993149352a3a87cd0625b3b61bfd31ab28977e1.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:51 -05:00
Tom Lendacky
7ed9abfe8e KVM: SVM: Support string IO operations for an SEV-ES guest
For an SEV-ES guest, string-based port IO is performed to a shared
(un-encrypted) page so that both the hypervisor and guest can read or
write to it and each see the contents.

For string-based port IO operations, invoke SEV-ES specific routines that
can complete the operation using common KVM port IO support.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <9d61daf0ffda496703717218f415cdc8fd487100.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:51 -05:00
Tom Lendacky
8f423a80d2 KVM: SVM: Support MMIO for an SEV-ES guest
For an SEV-ES guest, MMIO is performed to a shared (un-encrypted) page
so that both the hypervisor and guest can read or write to it and each
see the contents.

The GHCB specification provides software-defined VMGEXIT exit codes to
indicate a request for an MMIO read or an MMIO write. Add support to
recognize the MMIO requests and invoke SEV-ES specific routines that
can complete the MMIO operation. These routines use common KVM support
to complete the MMIO operation.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <af8de55127d5bcc3253d9b6084a0144c12307d4d.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:50 -05:00
Tom Lendacky
59e38b58de KVM: SVM: Create trace events for VMGEXIT MSR protocol processing
Add trace events for entry to and exit from VMGEXIT MSR protocol
processing. The vCPU will be common for the trace events. The MSR
protocol processing is guided by the GHCB GPA in the VMCB, so the GHCB
GPA will represent the input and output values for the entry and exit
events, respectively. Additionally, the exit event will contain the
return code for the event.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <c5b3b440c3e0db43ff2fc02813faa94fa54896b0.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:49 -05:00
Tom Lendacky
d523ab6ba2 KVM: SVM: Create trace events for VMGEXIT processing
Add trace events for entry to and exit from VMGEXIT processing. The vCPU
id and the exit reason will be common for the trace events. The exit info
fields will represent the input and output values for the entry and exit
events, respectively.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <25357dca49a38372e8f483753fb0c1c2a70a6898.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:49 -05:00
Tom Lendacky
e1d71116b6 KVM: SVM: Add support for SEV-ES GHCB MSR protocol function 0x100
The GHCB specification defines a GHCB MSR protocol using the lower
12-bits of the GHCB MSR (in the hypervisor this corresponds to the
GHCB GPA field in the VMCB).

Function 0x100 is a request for termination of the guest. The guest has
encountered some situation for which it has requested to be terminated.
The GHCB MSR value contains the reason for the request.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <f3a1f7850c75b6ea4101e15bbb4a3af1a203f1dc.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:48 -05:00
Tom Lendacky
d36946679e KVM: SVM: Add support for SEV-ES GHCB MSR protocol function 0x004
The GHCB specification defines a GHCB MSR protocol using the lower
12-bits of the GHCB MSR (in the hypervisor this corresponds to the
GHCB GPA field in the VMCB).

Function 0x004 is a request for CPUID information. Only a single CPUID
result register can be sent per invocation, so the protocol defines the
register that is requested. The GHCB MSR value is set to the CPUID
register value as per the specification via the VMCB GHCB GPA field.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <fd7ee347d3936e484c06e9001e340bf6387092cd.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:48 -05:00
Tom Lendacky
1edc14599e KVM: SVM: Add support for SEV-ES GHCB MSR protocol function 0x002
The GHCB specification defines a GHCB MSR protocol using the lower
12-bits of the GHCB MSR (in the hypervisor this corresponds to the
GHCB GPA field in the VMCB).

Function 0x002 is a request to set the GHCB MSR value to the SEV INFO as
per the specification via the VMCB GHCB GPA field.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <c23c163a505290a0d1b9efc4659b838c8c902cbc.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:47 -05:00
Tom Lendacky
291bd20d5d KVM: SVM: Add initial support for a VMGEXIT VMEXIT
SEV-ES adds a new VMEXIT reason code, VMGEXIT. Initial support for a
VMGEXIT includes mapping the GHCB based on the guest GPA, which is
obtained from a new VMCB field, and then validating the required inputs
for the VMGEXIT exit reason.

Since many of the VMGEXIT exit reasons correspond to existing VMEXIT
reasons, the information from the GHCB is copied into the VMCB control
exit code areas and KVM register areas. The standard exit handlers are
invoked, similar to standard VMEXIT processing. Before restarting the
vCPU, the GHCB is updated with any registers that have been updated by
the hypervisor.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <c6a4ed4294a369bd75c44d03bd7ce0f0c3840e50.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:47 -05:00
Tom Lendacky
e9093fd492 KVM: SVM: Prepare for SEV-ES exit handling in the sev.c file
This is a pre-patch to consolidate some exit handling code into callable
functions. Follow-on patches for SEV-ES exit handling will then be able
to use them from the sev.c file.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <5b8b0ffca8137f3e1e257f83df9f5c881c8a96a3.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:47 -05:00
Tom Lendacky
8164a5ffe4 KVM: SVM: Cannot re-initialize the VMCB after shutdown with SEV-ES
When a SHUTDOWN VMEXIT is encountered, normally the VMCB is re-initialized
so that the guest can be re-launched. But when a guest is running as an
SEV-ES guest, the VMSA cannot be re-initialized because it has been
encrypted. For now, just return -EINVAL to prevent a possible attempt at
a guest reset.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <aa6506000f6f3a574de8dbcdab0707df844cb00c.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:46 -05:00
Tom Lendacky
bc624d9f1b KVM: SVM: Do not allow instruction emulation under SEV-ES
When a guest is running as an SEV-ES guest, it is not possible to emulate
instructions. Add support to prevent instruction emulation.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <f6355ea3024fda0a3eb5eb99c6b62dca10d792bd.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:46 -05:00
Tom Lendacky
8d4846b9b1 KVM: SVM: Prevent debugging under SEV-ES
Since the guest register state of an SEV-ES guest is encrypted, debugging
is not supported. Update the code to prevent guest debugging when the
guest has protected state.

Additionally, an SEV-ES guest must only and always intercept DR7 reads and
writes. Update set_dr_intercepts() and clr_dr_intercepts() to account for
this.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <8db966fa2f9803d6454ce773863025d0e2e7f3cc.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:46 -05:00
Tom Lendacky
f1c6366e30 KVM: SVM: Add required changes to support intercepts under SEV-ES
When a guest is running under SEV-ES, the hypervisor cannot access the
guest register state. There are numerous places in the KVM code where
certain registers are accessed that are not allowed to be accessed (e.g.
RIP, CR0, etc). Add checks to prevent register accesses and add intercept
update support at various points within the KVM code.

Also, when handling a VMGEXIT, exceptions are passed back through the
GHCB. Since the RDMSR/WRMSR intercepts (may) inject a #GP on error,
update the SVM intercepts to handle this for SEV-ES guests.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
[Redo MSR part using the .complete_emulated_msr callback. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:45 -05:00
Paolo Bonzini
f9a4d62176 KVM: x86: introduce complete_emulated_msr callback
This will be used by SEV-ES to inject MSR failure via the GHCB.

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 05:20:34 -05:00
Tom Lendacky
add5e2f045 KVM: SVM: Add support for the SEV-ES VMSA
Allocate a page during vCPU creation to be used as the encrypted VM save
area (VMSA) for the SEV-ES guest. Provide a flag in the kvm_vcpu_arch
structure that indicates whether the guest state is protected.

When freeing a VMSA page that has been encrypted, the cache contents must
be flushed using the MSR_AMD64_VM_PAGE_FLUSH before freeing the page.

[ i386 build warnings ]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <fde272b17eec804f3b9db18c131262fe074015c5.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-14 11:09:32 -05:00
Tom Lendacky
916391a2d1 KVM: SVM: Add support for SEV-ES capability in KVM
Add support to KVM for determining if a system is capable of supporting
SEV-ES as well as determining if a guest is an SEV-ES guest.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <e66792323982c822350e40c7a1cf67ea2978a70b.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-14 11:09:31 -05:00
Tom Lendacky
9d4747d023 KVM: SVM: Remove the call to sev_platform_status() during setup
When both KVM support and the CCP driver are built into the kernel instead
of as modules, KVM initialization can happen before CCP initialization. As
a result, sev_platform_status() will return a failure when it is called
from sev_hardware_setup(), when this isn't really an error condition.

Since sev_platform_status() doesn't need to be called at this time anyway,
remove the invocation from sev_hardware_setup().

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <618380488358b56af558f2682203786f09a49483.1607620209.git.thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-14 11:09:30 -05:00
Uros Bizjak
3f1a18b9fa KVM/VMX/SVM: Move kvm_machine_check function to x86.h
Move kvm_machine_check to x86.h to avoid two exact copies
of the same function in kvm.c and svm.c.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Message-Id: <20201029135600.122392-1-ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-14 11:09:29 -05:00
Paolo Bonzini
39485ed95d KVM: x86: reinstate vendor-agnostic check on SPEC_CTRL cpuid bits
Until commit e7c587da1252 ("x86/speculation: Use synthetic bits for
IBRS/IBPB/STIBP"), KVM was testing both Intel and AMD CPUID bits before
allowing the guest to write MSR_IA32_SPEC_CTRL and MSR_IA32_PRED_CMD.
Testing only Intel bits on VMX processors, or only AMD bits on SVM
processors, fails if the guests are created with the "opposite" vendor
as the host.

While at it, also tweak the host CPU check to use the vendor-agnostic
feature bit X86_FEATURE_IBPB, since we only care about the availability
of the MSR on the host here and not about specific CPUID bits.

Fixes: e7c587da1252 ("x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP")
Cc: stable@vger.kernel.org
Reported-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-11 19:05:13 -05:00
Jacob Xu
a2b2d4bf50 kvm: svm: de-allocate svm_cpu_data for all cpus in svm_cpu_uninit()
The cpu arg for svm_cpu_uninit() was previously ignored resulting in the
per cpu structure svm_cpu_data not being de-allocated for all cpus.

Signed-off-by: Jacob Xu <jacobhxu@google.com>
Message-Id: <20201203205939.1783969-1-jacobhxu@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-04 03:47:58 -05:00
Paolo Bonzini
dee734a7de KVM: x86: adjust SEV for commit 7e8e6eed75e
Since the ASID is now stored in svm->asid, pre_sev_run should also place
it there and not directly in the VMCB control area.

Reported-by: Ashish Kalra <Ashish.Kalra@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-03 12:38:39 -05:00
Paolo Bonzini
8cce12b3c8 KVM: nSVM: set fixed bits by hand
SVM generally ignores fixed-1 bits.  Set them manually so that we
do not end up by mistake without those bits set in struct kvm_vcpu;
it is part of userspace API that KVM always returns value with the
bits set.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-27 12:46:36 -05:00
Chen Zhou
054409ab25 KVM: SVM: fix error return code in svm_create_vcpu()
Fix to return a negative error code from the error handling case
instead of 0 in function svm_create_vcpu(), as done elsewhere in this
function.

Fixes: f4c847a95654 ("KVM: SVM: refactor msr permission bitmap allocation")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Message-Id: <20201117025426.167824-1-chenzhou10@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-17 02:40:08 -05:00
Ashish Kalra
854c57f02b KVM: SVM: Fix offset computation bug in __sev_dbg_decrypt().
Fix offset computation in __sev_dbg_decrypt() to include the
source paddr before it is rounded down to be aligned to 16 bytes
as required by SEV API. This fixes incorrect guest memory dumps
observed when using qemu monitor.

Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Message-Id: <20201110224205.29444-1-Ashish.Kalra@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-16 13:59:09 -05:00
Paolo Bonzini
dc924b0624 KVM: SVM: check CR4 changes against vcpu->arch
Similarly to what vmx/vmx.c does, use vcpu->arch.cr4 to check if CR4
bits PGE, PKE and OSXSAVE have changed.  When switching between VMCB01
and VMCB02, CPUID has to be adjusted every time if CR4.PKE or CR4.OSXSAVE
change; without this patch, instead, CR4 would be checked against the
previous value for L2 on vmentry, and against the previous value for
L1 on vmexit, and CPUID would not be updated.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-16 13:14:22 -05:00