109 Commits

Author SHA1 Message Date
Paolo Bonzini
17d44a96f0 KVM: SEV: Prohibit migration of a VM that has mirrors
VMs that mirror an encryption context rely on the owner to keep the
ASID allocated.  Performing a KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
would cause a dangling ASID:

1. copy context from A to B (gets ref to A)
2. move context from A to L (moves ASID from A to L)
3. close L (releases ASID from L, B still references it)

The right way to do the handoff instead is to create a fresh mirror VM
on the destination first:

1. copy context from A to B (gets ref to A)
[later] 2. close B (releases ref to A)
3. move context from A to L (moves ASID from A to L)
4. copy context from L to M

So, catch the situation by adding a count of how many VMs are
mirroring this one's encryption context.

Fixes: 0b020f5af092 ("KVM: SEV: Add support for SEV-ES intra host migration")
Message-Id: <20211123005036.2954379-11-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:54:14 -05:00
Paolo Bonzini
817506df9d Merge branch 'kvm-5.16-fixes' into kvm-master
* Fixes for Xen emulation

* Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache

* Fixes for migration of 32-bit nested guests on 64-bit hypervisor

* Compilation fixes

* More SEV cleanups
2021-11-18 02:11:57 -05:00
Sean Christopherson
1bd00a4257 KVM: SEV: WARN if SEV-ES is marked active but SEV is not
WARN if the VM is tagged as SEV-ES but not SEV.  KVM relies on SEV and
SEV-ES being set atomically, and guards common flows with "is SEV", i.e.
observing SEV-ES without SEV means KVM has a fatal bug.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:27 -05:00
Paolo Bonzini
1f05833193 Merge branch 'kvm-sev-move-context' into kvm-master
Add support for AMD SEV and SEV-ES intra-host migration support.  Intra
host migration provides a low-cost mechanism for userspace VMM upgrades.

In the common case for intra host migration, we can rely on the normal
ioctls for passing data from one VMM to the next. SEV, SEV-ES, and other
confidential compute environments make most of this information opaque, and
render KVM ioctls such as "KVM_GET_REGS" irrelevant.  As a result, we need
the ability to pass this opaque metadata from one VMM to the next. The
easiest way to do this is to leave this data in the kernel, and transfer
ownership of the metadata from one KVM VM (or vCPU) to the next.  In-kernel
hand off makes it possible to move any data that would be
unsafe/impossible for the kernel to hand directly to userspace, and
cannot be reproduced using data that can be handed to userspace.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 11:02:58 -05:00
Peter Gonda
b56639318b KVM: SEV: Add support for SEV intra host migration
For SEV to work with intra host migration, contents of the SEV info struct
such as the ASID (used to index the encryption key in the AMD SP) and
the list of memory regions need to be transferred to the target VM.
This change adds a commands for a target VMM to get a source SEV VM's sev
info.

Signed-off-by: Peter Gonda <pgonda@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Cc: Marc Orr <marcorr@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <20211021174303.385706-3-pgonda@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:35:27 -05:00
Peter Gonda
b67a4cc35c KVM: SEV: Refactor out sev_es_state struct
Move SEV-ES vCPU metadata into new sev_es_state struct from vcpu_svm.

Signed-off-by: Peter Gonda <pgonda@google.com>
Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: Marc Orr <marcorr@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <20211021174303.385706-2-pgonda@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:35:26 -05:00
Linus Torvalds
d7e0a795bf ARM:
* More progress on the protected VM front, now with the full
   fixed feature set as well as the limitation of some hypercalls
   after initialisation.
 
 * Cleanup of the RAZ/WI sysreg handling, which was pointlessly
   complicated
 
 * Fixes for the vgic placement in the IPA space, together with a
   bunch of selftests
 
 * More memcg accounting of the memory allocated on behalf of a guest
 
 * Timer and vgic selftests
 
 * Workarounds for the Apple M1 broken vgic implementation
 
 * KConfig cleanups
 
 * New kvmarm.mode=none option, for those who really dislike us
 
 RISC-V:
 * New KVM port.
 
 x86:
 * New API to control TSC offset from userspace
 
 * TSC scaling for nested hypervisors on SVM
 
 * Switch masterclock protection from raw_spin_lock to seqcount
 
 * Clean up function prototypes in the page fault code and avoid
 repeated memslot lookups
 
 * Convey the exit reason to userspace on emulation failure
 
 * Configure time between NX page recovery iterations
 
 * Expose Predictive Store Forwarding Disable CPUID leaf
 
 * Allocate page tracking data structures lazily (if the i915
 KVM-GT functionality is not compiled in)
 
 * Cleanups, fixes and optimizations for the shadow MMU code
 
 s390:
 * SIGP Fixes
 
 * initial preparations for lazy destroy of secure VMs
 
 * storage key improvements/fixes
 
 * Log the guest CPNC
 
 Starting from this release, KVM-PPC patches will come from
 Michael Ellerman's PPC tree.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "ARM:

   - More progress on the protected VM front, now with the full fixed
     feature set as well as the limitation of some hypercalls after
     initialisation.

   - Cleanup of the RAZ/WI sysreg handling, which was pointlessly
     complicated

   - Fixes for the vgic placement in the IPA space, together with a
     bunch of selftests

   - More memcg accounting of the memory allocated on behalf of a guest

   - Timer and vgic selftests

   - Workarounds for the Apple M1 broken vgic implementation

   - KConfig cleanups

   - New kvmarm.mode=none option, for those who really dislike us

  RISC-V:

   - New KVM port.

  x86:

   - New API to control TSC offset from userspace

   - TSC scaling for nested hypervisors on SVM

   - Switch masterclock protection from raw_spin_lock to seqcount

   - Clean up function prototypes in the page fault code and avoid
     repeated memslot lookups

   - Convey the exit reason to userspace on emulation failure

   - Configure time between NX page recovery iterations

   - Expose Predictive Store Forwarding Disable CPUID leaf

   - Allocate page tracking data structures lazily (if the i915 KVM-GT
     functionality is not compiled in)

   - Cleanups, fixes and optimizations for the shadow MMU code

  s390:

   - SIGP Fixes

   - initial preparations for lazy destroy of secure VMs

   - storage key improvements/fixes

   - Log the guest CPNC

  Starting from this release, KVM-PPC patches will come from Michael
  Ellerman's PPC tree"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
  RISC-V: KVM: fix boolreturn.cocci warnings
  RISC-V: KVM: remove unneeded semicolon
  RISC-V: KVM: Fix GPA passed to __kvm_riscv_hfence_gvma_xyz() functions
  RISC-V: KVM: Factor-out FP virtualization into separate sources
  KVM: s390: add debug statement for diag 318 CPNC data
  KVM: s390: pv: properly handle page flags for protected guests
  KVM: s390: Fix handle_sske page fault handling
  KVM: x86: SGX must obey the KVM_INTERNAL_ERROR_EMULATION protocol
  KVM: x86: On emulation failure, convey the exit reason, etc. to userspace
  KVM: x86: Get exit_reason as part of kvm_x86_ops.get_exit_info
  KVM: x86: Clarify the kvm_run.emulation_failure structure layout
  KVM: s390: Add a routine for setting userspace CPU state
  KVM: s390: Simplify SIGP Set Arch handling
  KVM: s390: pv: avoid stalls when making pages secure
  KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vm
  KVM: s390: pv: avoid double free of sida page
  KVM: s390: pv: add macros for UVC CC values
  s390/mm: optimize reset_guest_reference_bit()
  s390/mm: optimize set_guest_storage_key()
  s390/mm: no need for pte_alloc_map_lock() if we know the pmd is present
  ...
2021-11-02 11:24:14 -07:00
Linus Torvalds
43aa0a195f objtool updates:
- Improve retpoline code patching by separating it from alternatives which
    reduces memory footprint and allows to do better optimizations in the
    actual runtime patching.
 
  - Add proper retpoline support for x86/BPF
 
  - Address noinstr warnings in x86/kvm, lockdep and paravirtualization code
 
  - Add support to handle pv_opsindirect calls in the noinstr analysis
 
  - Classify symbols upfront and cache the result to avoid redundant
    str*cmp() invocations.
 
  - Add a CFI hash to reduce memory consumption which also reduces runtime
    on a allyesconfig by ~50%
 
  - Adjust XEN code to make objtool handling more robust and as a side
    effect to prevent text fragmentation due to placement of the hypercall
    page.
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Merge tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Thomas Gleixner:

 - Improve retpoline code patching by separating it from alternatives
   which reduces memory footprint and allows to do better optimizations
   in the actual runtime patching.

 - Add proper retpoline support for x86/BPF

 - Address noinstr warnings in x86/kvm, lockdep and paravirtualization
   code

 - Add support to handle pv_opsindirect calls in the noinstr analysis

 - Classify symbols upfront and cache the result to avoid redundant
   str*cmp() invocations.

 - Add a CFI hash to reduce memory consumption which also reduces
   runtime on a allyesconfig by ~50%

 - Adjust XEN code to make objtool handling more robust and as a side
   effect to prevent text fragmentation due to placement of the
   hypercall page.

* tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  bpf,x86: Respect X86_FEATURE_RETPOLINE*
  bpf,x86: Simplify computing label offsets
  x86,bugs: Unconditionally allow spectre_v2=retpoline,amd
  x86/alternative: Add debug prints to apply_retpolines()
  x86/alternative: Try inline spectre_v2=retpoline,amd
  x86/alternative: Handle Jcc __x86_indirect_thunk_\reg
  x86/alternative: Implement .retpoline_sites support
  x86/retpoline: Create a retpoline thunk array
  x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h
  x86/asm: Fixup odd GEN-for-each-reg.h usage
  x86/asm: Fix register order
  x86/retpoline: Remove unused replacement symbols
  objtool,x86: Replace alternatives with .retpoline_sites
  objtool: Shrink struct instruction
  objtool: Explicitly avoid self modifying code in .altinstr_replacement
  objtool: Classify symbols
  objtool: Support pv_opsindirect calls for noinstr
  x86/xen: Rework the xen_{cpu,irq,mmu}_opsarrays
  x86/xen: Mark xen_force_evtchn_callback() noinstr
  x86/xen: Make irq_disable() noinstr
  ...
2021-11-01 13:24:43 -07:00
Paolo Bonzini
9f1ee7b169 KVM: SEV-ES: reduce ghcb_sa_len to 32 bits
The size of the GHCB scratch area is limited to 16 KiB (GHCB_SCRATCH_AREA_LIMIT),
so there is no need for it to be a u64.  This fixes a build error on 32-bit
systems:

i686-linux-gnu-ld: arch/x86/kvm/svm/sev.o: in function `sev_es_string_io:
sev.c:(.text+0x110f): undefined reference to `__udivdi3'

Cc: stable@vger.kernel.org
Fixes: 019057bd73d1 ("KVM: SEV-ES: fix length of string I/O")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-18 14:07:19 -04:00
Peter Zijlstra
b08cadbd3b Merge branch 'objtool/urgent'
Fixup conflicts.

# Conflicts:
#	tools/objtool/check.c
2021-10-07 00:40:17 +02:00
Maxim Levitsky
5228eb96a4 KVM: x86: nSVM: implement nested TSC scaling
This was tested by booting a nested guest with TSC=1Ghz,
observing the clocks, and doing about 100 cycles of migration.

Note that qemu patch is needed to support migration because
of a new MSR that needs to be placed in the migration state.

The patch will be sent to the qemu mailing list soon.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210914154825.104886-14-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-01 03:44:46 -04:00
Sean Christopherson
9ebe530b9f KVM: SVM: Move RESET emulation to svm_vcpu_reset()
Move RESET emulation for SVM vCPUs to svm_vcpu_reset(), and drop an extra
init_vmcb() from svm_create_vcpu() in the process.  Hopefully KVM will
someday expose a dedicated RESET ioctl(), and in the meantime separating
"create" from "RESET" is a nice cleanup.

Keep the call to svm_switch_vmcb() so that misuse of svm->vmcb at worst
breaks the guest, e.g. premature accesses doesn't cause a NULL pointer
dereference.

Cc: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210921000303.400537-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30 04:27:07 -04:00
Maxim Levitsky
e85d3e7b49 KVM: x86: SVM: call KVM_REQ_GET_NESTED_STATE_PAGES on exit from SMM mode
Currently the KVM_REQ_GET_NESTED_STATE_PAGES on SVM only reloads PDPTRs,
and MSR bitmap, with former not really needed for SMM as SMM exit code
reloads them again from SMRAM'S CR3, and later happens to work
since MSR bitmap isn't modified while in SMM.

Still it is better to be consistient with VMX.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210913140954.165665-5-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22 10:33:17 -04:00
Peter Zijlstra
aee045ed0a x86/kvm: Always inline to_svm()
vmlinux.o: warning: objtool: svm_vcpu_enter_exit()+0x13: call to to_svm() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210624095148.066347165@infradead.org
2021-09-15 15:51:46 +02:00
Peter Zijlstra
2b2f72d4d8 x86/kvm: Always inline sev_*guest()
vmlinux.o: warning: objtool: svm_vcpu_enter_exit()+0x4d: call to sev_es_guest() leaves .noinstr.text section
vmlinux.o: warning: objtool: svm_vcpu_enter_exit()+0x50: call to sev_guest() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210624095147.880513802@infradead.org
2021-09-15 15:51:45 +02:00
Maxim Levitsky
73143035c2 KVM: SVM: AVIC: drop unsupported AVIC base relocation code
APIC base relocation is not supported anyway and won't work
correctly so just drop the code that handles it and keep AVIC
MMIO bar at the default APIC base.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210810205251.424103-17-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-20 16:06:31 -04:00
Maxim Levitsky
30eed56a7e KVM: SVM: remove svm_toggle_avic_for_irq_window
Now that kvm_request_apicv_update doesn't need to drop the kvm->srcu lock,
we can call kvm_request_apicv_update directly.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210810205251.424103-13-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-20 16:06:26 -04:00
Maxim Levitsky
36222b117e KVM: x86: don't disable APICv memslot when inhibited
Thanks to the former patches, it is now possible to keep the APICv
memslot always enabled, and it will be invisible to the guest
when it is inhibited

This code is based on a suggestion from Sean Christopherson:
https://lkml.org/lkml/2021/7/19/2970

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210810205251.424103-9-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-20 16:06:22 -04:00
Vitaly Kuznetsov
2bb16bea5f KVM: nSVM: Swap the parameter order for svm_copy_vmrun_state()/svm_copy_vmloadsave_state()
Make svm_copy_vmrun_state()/svm_copy_vmloadsave_state() interface match
'memcpy(dest, src)' to avoid any confusion.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210719090322.625277-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-26 08:09:46 -04:00
Vitaly Kuznetsov
9a9e74819b KVM: nSVM: Rename nested_svm_vmloadsave() to svm_copy_vmloadsave_state()
To match svm_copy_vmrun_state(), rename nested_svm_vmloadsave() to
svm_copy_vmloadsave_state().

Opportunistically add missing braces to 'else' branch in
vmload_vmsave_interception().

No functional change intended.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210716144104.465269-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-26 08:09:36 -04:00
Vitaly Kuznetsov
bb00bd9c08 KVM: nSVM: Restore nested control upon leaving SMM
If the VM was migrated while in SMM, no nested state was saved/restored,
and therefore svm_leave_smm has to load both save and control area
of the vmcb12. Save area is already loaded from HSAVE area,
so now load the control area as well from the vmcb12.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210628104425.391276-6-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-15 10:19:44 -04:00
Vitaly Kuznetsov
0a75829076 KVM: nSVM: Introduce svm_copy_vmrun_state()
Separate the code setting non-VMLOAD-VMSAVE state from
svm_set_nested_state() into its own function. This is going to be
re-used from svm_enter_smm()/svm_leave_smm().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210628104425.391276-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-15 10:19:43 -04:00
Maxim Levitsky
4b639a9f82 KVM: SVM: add module param to control the #SMI interception
In theory there are no side effects of not intercepting #SMI,
because then #SMI becomes transparent to the OS and the KVM.

Plus an observation on recent Zen2 CPUs reveals that these
CPUs ignore #SMI interception and never deliver #SMI VMexits.

This is also useful to test nested KVM to see that L1
handles #SMIs correctly in case when L1 doesn't intercept #SMI.

Finally the default remains the same, the SMI are intercepted
by default thus this patch doesn't have any effect unless
non default module param value is used.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210707125100.677203-4-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-15 10:19:42 -04:00
Paolo Bonzini
c3ab0e28a4 Merge branch 'topic/ppc-kvm' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux into HEAD
- Support for the H_RPT_INVALIDATE hypercall

- Conversion of Book3S entry/exit to C

- Bug fixes
2021-06-23 07:30:41 -04:00
Vineeth Pillai
c4327f15df KVM: SVM: hyper-v: Enlightened MSR-Bitmap support
Enlightened MSR-Bitmap as per TLFS:

 "The L1 hypervisor may collaborate with the L0 hypervisor to make MSR
  accesses more efficient. It can enable enlightened MSR bitmaps by setting
  the corresponding field in the enlightened VMCS to 1. When enabled, L0
  hypervisor does not monitor the MSR bitmaps for changes. Instead, the L1
  hypervisor must invalidate the corresponding clean field after making
  changes to one of the MSR bitmaps."

Enable this for SVM.

Related VMX changes:
commit ceef7d10dfb6 ("KVM: x86: VMX: hyper-v: Enlightened MSR-Bitmap support")

Signed-off-by: Vineeth Pillai <viremana@linux.microsoft.com>
Message-Id: <87df0710f95d28b91cc4ea014fc4d71056eebbee.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:37 -04:00
Vineeth Pillai
59d21d67f3 KVM: SVM: Software reserved fields
SVM added support for certain reserved fields to be used by
software or hypervisor. Add the following reserved fields:
  - VMCB offset 0x3e0 - 0x3ff
  - Clean bit 31
  - SVM intercept exit code 0xf0000000

Later patches will make use of this for supporting Hyper-V
nested virtualization enhancements.

Signed-off-by: Vineeth Pillai <viremana@linux.microsoft.com>
Message-Id: <a1f17a43a8e9e751a1a9cc0281649d71bdbf721b.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:37 -04:00
Vitaly Kuznetsov
fdf513e37a KVM: x86: Use common 'enable_apicv' variable for both APICv and AVIC
Unify VMX and SVM code by moving APICv/AVIC enablement tracking to common
'enable_apicv' variable. Note: unlike APICv, AVIC is disabled by default.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210609150911.1471882-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:33 -04:00
Paolo Bonzini
28a4aa1160 KVM: SVM: make the avic parameter a bool
Make it consistent with kvm_intel.enable_apicv.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-24 13:10:27 -04:00
Linus Torvalds
ccb013c29d - Enable -Wundef for the compressed kernel build stage
- Reorganize SEV code to streamline and simplify future development
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Merge tag 'x86_urgent_for_v5.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:
 "The three SEV commits are not really urgent material. But we figured
  since getting them in now will avoid a huge amount of conflicts
  between future SEV changes touching tip, the kvm and probably other
  trees, sending them to you now would be best.

  The idea is that the tip, kvm etc branches for 5.14 will all base
  ontop of -rc2 and thus everything will be peachy. What is more, those
  changes are purely mechanical and defines movement so they should be
  fine to go now (famous last words).

  Summary:

   - Enable -Wundef for the compressed kernel build stage

   - Reorganize SEV code to streamline and simplify future development"

* tag 'x86_urgent_for_v5.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/compressed: Enable -Wundef
  x86/msr: Rename MSR_K8_SYSCFG to MSR_AMD64_SYSCFG
  x86/sev: Move GHCB MSR protocol and NAE definitions in a common header
  x86/sev-es: Rename sev-es.{ch} to sev.{ch}
2021-05-16 09:31:06 -07:00
Brijesh Singh
b81fc74d53 x86/sev: Move GHCB MSR protocol and NAE definitions in a common header
The guest and the hypervisor contain separate macros to get and set
the GHCB MSR protocol and NAE event fields. Consolidate the GHCB
protocol definitions and helper macros in one place.

Leave the supported protocol version define in separate files to keep
the guest and hypervisor flexibility to support different GHCB version
in the same release.

There is no functional change intended.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20210427111636.1207-3-brijesh.singh@amd.com
2021-05-10 07:46:39 +02:00
Tom Lendacky
ce7ea0cfdc KVM: SVM: Move GHCB unmapping to fix RCU warning
When an SEV-ES guest is running, the GHCB is unmapped as part of the
vCPU run support. However, kvm_vcpu_unmap() triggers an RCU dereference
warning with CONFIG_PROVE_LOCKING=y because the SRCU lock is released
before invoking the vCPU run support.

Move the GHCB unmapping into the prepare_guest_switch callback, which is
invoked while still holding the SRCU lock, eliminating the RCU dereference
warning.

Fixes: 291bd20d5d88 ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <b2f9b79d15166f2c3e4375c0d9bc3268b7696455.1620332081.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-07 06:06:23 -04:00
Sean Christopherson
a5c1c5aad6 KVM: SVM: Drop redundant svm_sev_enabled() helper
Replace calls to svm_sev_enabled() with direct checks on sev_enabled, or
in the case of svm_mem_enc_op, simply drop the call to svm_sev_enabled().
This effectively replaces checks against a valid max_sev_asid with checks
against sev_enabled.  sev_enabled is forced off by sev_hardware_setup()
if max_sev_asid is invalid, all call sites are guaranteed to run after
sev_hardware_setup(), and all of the checks care about SEV being fully
enabled (as opposed to intentionally handling the scenario where
max_sev_asid is valid but SEV enabling fails due to OOM).

Reviewed by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422021125.3417167-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-26 05:27:17 -04:00
Sean Christopherson
b95c221cac KVM: SVM: Move SEV VMCB tracking allocation to sev.c
Move the allocation of the SEV VMCB array to sev.c to help pave the way
toward encapsulating SEV enabling wholly within sev.c.

No functional change intended.

Reviewed by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422021125.3417167-13-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-26 05:27:17 -04:00
Paolo Bonzini
d9db0fd6c5 KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features
Add a reverse-CPUID entry for the memory encryption word, 0x8000001F.EAX,
and use it to override the supported CPUID flags reported to userspace.
Masking the reported CPUID flags avoids over-reporting KVM support, e.g.
without the mask a SEV-SNP capable CPU may incorrectly advertise SNP
support to userspace.

Clear SEV/SEV-ES if their corresponding module parameters are disabled,
and clear the memory encryption leaf completely if SEV is not fully
supported in KVM.  Advertise SME_COHERENT in addition to SEV and SEV-ES,
as the guest can use SME_COHERENT to avoid CLFLUSH operations.

Explicitly omit SME and VM_PAGE_FLUSH from the reporting.  These features
are used by KVM, but are not exposed to the guest, e.g. guest access to
related MSRs will fault.

Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422021125.3417167-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-26 05:27:15 -04:00
Sean Christopherson
e8126bdaf1 KVM: SVM: Move SEV module params/variables to sev.c
Unconditionally invoke sev_hardware_setup() when configuring SVM and
handle clearing the module params/variable 'sev' and 'sev_es' in
sev_hardware_setup().  This allows making said variables static within
sev.c and reduces the odds of a collision with guest code, e.g. the guest
side of things has already laid claim to 'sev_enabled'.

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422021125.3417167-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-26 05:27:15 -04:00
Sean Christopherson
844d69c26d KVM: SVM: Delay restoration of host MSR_TSC_AUX until return to userspace
Use KVM's "user return MSRs" framework to defer restoring the host's
MSR_TSC_AUX until the CPU returns to userspace.  Add/improve comments to
clarify why MSR_TSC_AUX is intercepted on both RDMSR and WRMSR, and why
it's safe for KVM to keep the guest's value loaded even if KVM is
scheduled out.

Cc: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210423223404.3860547-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-26 05:26:13 -04:00
Paolo Bonzini
fd49e8ee70 Merge branch 'kvm-sev-cgroup' into HEAD 2021-04-22 13:19:01 -04:00
Nathan Tempelman
54526d1fd5 KVM: x86: Support KVM VMs sharing SEV context
Add a capability for userspace to mirror SEV encryption context from
one vm to another. On our side, this is intended to support a
Migration Helper vCPU, but it can also be used generically to support
other in-guest workloads scheduled by the host. The intention is for
the primary guest and the mirror to have nearly identical memslots.

The primary benefits of this are that:
1) The VMs do not share KVM contexts (think APIC/MSRs/etc), so they
can't accidentally clobber each other.
2) The VMs can have different memory-views, which is necessary for post-copy
migration (the migration vCPUs on the target need to read and write to
pages, when the primary guest would VMEXIT).

This does not change the threat model for AMD SEV. Any memory involved
is still owned by the primary guest and its initial state is still
attested to through the normal SEV_LAUNCH_* flows. If userspace wanted
to circumvent SEV, they could achieve the same effect by simply attaching
a vCPU to the primary VM.
This patch deliberately leaves userspace in charge of the memslots for the
mirror, as it already has the power to mess with them in the primary guest.

This patch does not support SEV-ES (much less SNP), as it does not
handle handing off attested VMSAs to the mirror.

For additional context, we need a Migration Helper because SEV PSP
migration is far too slow for our live migration on its own. Using
an in-guest migrator lets us speed this up significantly.

Signed-off-by: Nathan Tempelman <natet@google.com>
Message-Id: <20210408223214.2582277-1-natet@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-21 12:20:02 -04:00
Krish Sadhukhan
47903dc10e KVM: SVM: Define actual size of IOPM and MSRPM tables
Define the actual size of the IOPM and MSRPM tables so that the actual size
can be used when initializing them and when checking the consistency of their
physical address.
These #defines are placed in svm.h so that they can be shared.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Message-Id: <20210412215611.110095-2-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-20 04:18:56 -04:00
Sean Christopherson
554cf31474 KVM: SVM: Add a comment to clarify what vcpu_svm.vmcb points at
Add a comment above the declaration of vcpu_svm.vmcb to call out that it
is simply a shorthand for current_vmcb->ptr.  The myriad accesses to
svm->vmcb are quite confusing without this crucial detail.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210406171811.4043363-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-20 04:18:49 -04:00
Sean Christopherson
d1788191fd KVM: SVM: Drop vcpu_svm.vmcb_pa
Remove vmcb_pa from vcpu_svm and simply read current_vmcb->pa directly in
the one path where it is consumed.  Unlike svm->vmcb, use of the current
vmcb's address is very limited, as evidenced by the fact that its use
can be trimmed to a single dereference.

Opportunistically add a comment about using vmcb01 for VMLOAD/VMSAVE, at
first glance using vmcb01 instead of vmcb_pa looks wrong.

No functional change intended.

Cc: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210406171811.4043363-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-20 04:18:49 -04:00
Maxim Levitsky
adc2a23734 KVM: nSVM: improve SYSENTER emulation on AMD
Currently to support Intel->AMD migration, if CPU vendor is GenuineIntel,
we emulate the full 64 value for MSR_IA32_SYSENTER_{EIP|ESP}
msrs, and we also emulate the sysenter/sysexit instruction in long mode.

(Emulator does still refuse to emulate sysenter in 64 bit mode, on the
ground that the code for that wasn't tested and likely has no users)

However when virtual vmload/vmsave is enabled, the vmload instruction will
update these 32 bit msrs without triggering their msr intercept,
which will lead to having stale values in kvm's shadow copy of these msrs,
which relies on the intercept to be up to date.

Fix/optimize this by doing the following:

1. Enable the MSR intercepts for SYSENTER MSRs iff vendor=GenuineIntel
   (This is both a tiny optimization and also ensures that in case
   the guest cpu vendor is AMD, the msrs will be 32 bit wide as
   AMD defined).

2. Store only high 32 bit part of these msrs on interception and combine
   it with hardware msr value on intercepted read/writes
   iff vendor=GenuineIntel.

3. Disable vmload/vmsave virtualization if vendor=GenuineIntel.
   (It is somewhat insane to set vendor=GenuineIntel and still enable
   SVM for the guest but well whatever).
   Then zero the high 32 bit parts when kvm intercepts and emulates vmload.

Thanks a lot to Paulo Bonzini for helping me with fixing this in the most
correct way.

This patch fixes nested migration of 32 bit nested guests, that was
broken because incorrect cached values of SYSENTER msrs were stored in
the migration stream if L1 changed these msrs with
vmload prior to L2 entry.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210401111928.996871-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-17 08:30:59 -04:00
Vipin Sharma
7aef27f0b2 svm/sev: Register SEV and SEV-ES ASIDs to the misc controller
Secure Encrypted Virtualization (SEV) and Secure Encrypted
Virtualization - Encrypted State (SEV-ES) ASIDs are used to encrypt KVMs
on AMD platform. These ASIDs are available in the limited quantities on
a host.

Register their capacity and usage to the misc controller for tracking
via cgroups.

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: David Rientjes <rientjes@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-04-04 13:34:46 -04:00
Cathy Avery
8173396e94 KVM: nSVM: Optimize vmcb12 to vmcb02 save area copies
Use the vmcb12 control clean field to determine which vmcb12.save
registers were marked dirty in order to minimize register copies
when switching from L1 to L2. Those vmcb12 registers marked as dirty need
to be copied to L0's vmcb02 as they will be used to update the vmcb
state cache for the L2 VMRUN.  In the case where we have a different
vmcb12 from the last L2 VMRUN all vmcb12.save registers must be
copied over to L2.save.

Tested:
kvm-unit-tests
kvm selftests
Fedora L1 L2

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cathy Avery <cavery@redhat.com>
Message-Id: <20210301200844.2000-1-cavery@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-15 04:43:26 -04:00
Sean Christopherson
3a87c7e0d1 KVM: nSVM: Add helper to synthesize nested VM-Exit without collateral
Add a helper to consolidate boilerplate for nested VM-Exits that don't
provide any data in exit_info_*.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210302174515.2812275-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-15 04:43:16 -04:00
Paolo Bonzini
6312975417 KVM: SVM: Pass struct kvm_vcpu to exit handlers (and many, many other places)
Refactor the svm_exit_handlers API to pass @vcpu instead of @svm to
allow directly invoking common x86 exit handlers (in a future patch).
Opportunistically convert an absurd number of instances of 'svm->vcpu'
to direct uses of 'vcpu' to avoid pointless casting.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210205005750.3841462-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-15 04:43:09 -04:00
Paolo Bonzini
9e8f0fbfff KVM: nSVM: rename functions and variables according to vmcbXY nomenclature
Now that SVM is using a separate vmcb01 and vmcb02 (and also uses the vmcb12
naming) we can give clearer names to functions that write to and read
from those VMCBs.  Likewise, variables and parameters can be renamed
from nested_vmcb to vmcb12.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-15 04:42:31 -04:00
Cathy Avery
193015adf4 KVM: nSVM: Track the ASID generation of the vmcb vmrun through the vmcb
This patch moves the asid_generation from the vcpu to the vmcb
in order to track the ASID generation that was active the last
time the vmcb was run. If sd->asid_generation changes between
two runs, the old ASID is invalid and must be changed.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cathy Avery <cavery@redhat.com>
Message-Id: <20210112164313.4204-3-cavery@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-15 04:42:30 -04:00
Cathy Avery
af18fa775d KVM: nSVM: Track the physical cpu of the vmcb vmrun through the vmcb
This patch moves the physical cpu tracking from the vcpu
to the vmcb in svm_switch_vmcb. If either vmcb01 or vmcb02
change physical cpus from one vmrun to the next the vmcb's
previous cpu is preserved for comparison with the current
cpu and the vmcb is marked dirty if different. This prevents
the processor from using old cached data for a vmcb that may
have been updated on a prior run on a different processor.

It also moves the physical cpu check from svm_vcpu_load
to pre_svm_run as the check only needs to be done at run.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cathy Avery <cavery@redhat.com>
Message-Id: <20210112164313.4204-2-cavery@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-15 04:42:29 -04:00
Cathy Avery
4995a3685f KVM: SVM: Use a separate vmcb for the nested L2 guest
svm->vmcb will now point to a separate vmcb for L1 (not nested) or L2
(nested).

The main advantages are removing get_host_vmcb and hsave, in favor of
concepts that are shared with VMX.

We don't need anymore to stash the L1 registers in hsave while L2
runs, but we need to copy the VMLOAD/VMSAVE registers from VMCB01 to
VMCB02 and back.  This more or less has the same cost, but code-wise
nested_svm_vmloadsave can be reused.

This patch omits several optimizations that are possible:

- for simplicity there is some wholesale copying of vmcb.control areas
which can go away.

- we should be able to better use the VMCB01 and VMCB02 clean bits.

- another possibility is to always use VMCB01 for VMLOAD and VMSAVE,
thus avoiding the copy of VMLOAD/VMSAVE registers from VMCB01 to
VMCB02 and back.

Tested:
kvm-unit-tests
kvm self tests
Loaded fedora nested guest on fedora

Signed-off-by: Cathy Avery <cavery@redhat.com>
Message-Id: <20201011184818.3609-3-cavery@redhat.com>
[Fix conflicts; keep VMCB02 G_PAT up to date whenever guest writes the
 PAT MSR; do not copy CR4 over from VMCB01 as it is not needed anymore; add
 a few more comments. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-15 04:42:28 -04:00