Rework NMI VM-Exit handling to invoke the kernel handler by function
call instead of INTn. INTn microcode is relatively expensive, and
aligning the IRQ and NMI handling will make it easier to update KVM
should some newfangled method for invoking the handlers come along.
Suggested-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200915191505.10355-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the asm blob that invokes the appropriate IRQ handler after VM-Exit
into a proper subroutine. Unconditionally create a stack frame in the
subroutine so that, as objtool sees things, the function has standard
stack behavior. The dynamic stack adjustment makes using unwind hints
problematic.
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200915191505.10355-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace the existing kvm_x86_ops.need_emulation_on_page_fault() with a
more generic is_emulatable(), and unconditionally call the new function
in x86_emulate_instruction().
KVM will use the generic hook to support multiple security related
technologies that prevent emulation in one way or another. Similar to
the existing AMD #NPF case where emulation of the current instruction is
not possible due to lack of information, AMD's SEV-ES and Intel's SGX
and TDX will introduce scenarios where emulation is impossible due to
the guest's register state being inaccessible. And again similar to the
existing #NPF case, emulation can be initiated by kvm_mmu_page_fault(),
i.e. outside of the control of vendor-specific code.
While the cause and architecturally visible behavior of the various
cases are different, e.g. SGX will inject a #UD, AMD #NPF is a clean
resume or complete shutdown, and SEV-ES and TDX "return" an error, the
impact on the common emulation code is identical: KVM must stop
emulation immediately and resume the guest.
Query is_emulatable() in handle_ud() as well so that the
force_emulation_prefix code doesn't incorrectly modify RIP before
calling emulate_instruction() in the absurdly unlikely scenario that
KVM encounters forced emulation in conjunction with "do not emulate".
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200915232702.15945-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use __GFP_ZERO while alloc_page().
Signed-off-by: Haiwei Li <lihaiwei@tencent.com>
Message-Id: <20200916083621.5512-1-lihaiwei.kernel@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, prepare_vmcs02_early() does not check if the "unrestricted guest"
VM-execution control in vmcs12 is turned off and leaves the corresponding
bit on in vmcs02. Due to this setting, vmentry checks which are supposed to
render the nested guest state as invalid when this VM-execution control is
not set, are passing in hardware.
This patch turns off the "unrestricted guest" VM-execution control in vmcs02
if vmcs12 has turned it off.
Suggested-by: Jim Mattson <jmattson@google.com>
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Message-Id: <20200921081027.23047-2-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
MSR reads/writes should always access the L1 state, since the (nested)
hypervisor should intercept all the msrs it wants to adjust, and these
that it doesn't should be read by the guest as if the host had read it.
However IA32_TSC is an exception. Even when not intercepted, guest still
reads the value + TSC offset.
The write however does not take any TSC offset into account.
This is documented in Intel's SDM and seems also to happen on AMD as well.
This creates a problem when userspace wants to read the IA32_TSC value and then
write it. (e.g for migration)
In this case it reads L2 value but write is interpreted as an L1 value.
To fix this make the userspace initiated reads of IA32_TSC return L1 value
as well.
Huge thanks to Dave Gilbert for helping me understand this very confusing
semantic of MSR writes.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200921103805.9102-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make use of the struct_size() helper to avoid any potential type
mistakes and protect against potential integer overflows
Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure
Suggested-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com>
Message-Id: <20200918120500.954436-1-rkovhaev@gmail.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The following intercept bit has been added to support VMEXIT
for INVPCID instruction:
Code Name Cause
A2h VMEXIT_INVPCID INVPCID instruction
The following bit has been added to the VMCB layout control area
to control intercept of INVPCID:
Byte Offset Bit(s) Function
14h 2 intercept INVPCID
Enable the interceptions when the the guest is running with shadow
page table enabled and handle the tlbflush based on the invpcid
instruction type.
For the guests with nested page table (NPT) support, the INVPCID
feature works as running it natively. KVM does not need to do any
special handling in this case.
AMD documentation for INVPCID feature is available at "AMD64
Architecture Programmer’s Manual Volume 2: System Programming,
Pub. 24593 Rev. 3.34(or later)"
The documentation can be obtained at the links below:
Link: https://www.amd.com/system/files/TechDocs/24593.pdf
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985255929.11252.17346684135277453258.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
INVPCID instruction handling is mostly same across both VMX and
SVM. So, move the code to common x86.c.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985255212.11252.10322694343971983487.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Handling of kvm_read/write_guest_virt*() errors can be moved to common
code. The same code can be used by both VMX and SVM.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985254493.11252.6603092560732507607.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The new intercept bits have been added in vmcb control area to support
few more interceptions. Here are the some of them.
- INTERCEPT_INVLPGB,
- INTERCEPT_INVLPGB_ILLEGAL,
- INTERCEPT_INVPCID,
- INTERCEPT_MCOMMIT,
- INTERCEPT_TLBSYNC,
Add a new intercept word in vmcb_control_area to support these instructions.
Also update kvm_nested_vmrun trace function to support the new addition.
AMD documentation for these instructions is available at "AMD64
Architecture Programmer’s Manual Volume 2: System Programming, Pub. 24593
Rev. 3.34(or later)"
The documentation can be obtained at the links below:
Link: https://www.amd.com/system/files/TechDocs/24593.pdf
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985251547.11252.16994139329949066945.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Convert all the intercepts to one array of 32 bit vectors in
vmcb_control_area. This makes it easy for future intercept vector
additions. Also update trace functions.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985250813.11252.5736581193881040525.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Modify intercept_exceptions to generic intercepts in vmcb_control_area. Use
the generic vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept to
set/clear/test the intercept_exceptions bits.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985250037.11252.1361972528657052410.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Modify intercept_dr to generic intercepts in vmcb_control_area. Use
the generic vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept
to set/clear/test the intercept_dr bits.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985249255.11252.10000868032136333355.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Change intercept_cr to generic intercepts in vmcb_control_area.
Use the new vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept
where applicable.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985248506.11252.9081085950784508671.stgit@bmoger-ubuntu>
[Change constant names. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is in preparation for the future intercept vector additions.
Add new functions vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept
using kernel APIs __set_bit, __clear_bit and test_bit espectively.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985247876.11252.16039238014239824460.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
host_intercept_exceptions is not used anywhere. Clean it up.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <159985252277.11252.8819848322175521354.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Kernel coding style suggests not to use labels like error1,error2
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827171145.374620-6-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Another small refactoring.
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827171145.374620-5-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace svm_vcpu_init_msrpm with svm_vcpu_alloc_msrpm, that also allocates
the msr bitmap and add svm_vcpu_free_msrpm to free it.
This will be used later to move the nested msr permission bitmap allocation
to nested.c
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827171145.374620-4-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is to be more consistient with VMX, and to support
upcoming addition of vmcb02
Hopefully no functional changes.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827171145.374620-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The 'page' is to hold the vcpu's vmcb so name it as such to
avoid confusion.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20200827171145.374620-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All the checks in lapic_timer_int_injected(), __kvm_wait_lapic_expire(), and
these function calls waste cpu cycles when the timer mode is not tscdeadline.
We can observe ~1.3% world switch time overhead by kvm-unit-tests/vmexit.flat
vmcall testing on AMD server. This patch reduces the world switch latency
caused by timer_advance_ns feature when the timer mode is not tscdeadline by
simpling move the check against apic->lapic_timer.expired_tscdeadline much
earlier.
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1599731444-3525-7-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The kick after setting KVM_REQ_PENDING_TIMER is used to handle the timer
fires on a different pCPU which vCPU is running on. This kick costs about
1000 clock cycles and we don't need this when injecting already-expired
timer or when using the VMX preemption timer because
kvm_lapic_expired_hv_timer() is called from the target vCPU.
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1599731444-3525-6-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Check apic_lvtt_tscdeadline() mode directly instead of apic_lvtt_oneshot()
and apic_lvtt_period() to guarantee the timer is in tsc-deadline mode when
wrmsr MSR_IA32_TSCDEADLINE.
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1599731444-3525-3-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Return 0 when getting the tscdeadline timer if the lapic is hw disabled.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1599731444-3525-2-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There is missing apic map recalculation after updating DFR, if it is
INIT RESET, in x2apic mode, local apic is software enabled before.
This patch fix it by introducing the function kvm_apic_set_dfr() to
be called in INIT RESET handling path.
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1597827327-25055-1-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There is no need to calculate wildcard in each iteration
since wildcard is not changed.
Signed-off-by: Yi Li <yili@winhong.com>
Message-Id: <20200911055652.3041762-1-yili@winhong.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The nested VMX controls MSRs can be initialized by the global capability
values stored in vmcs_config.
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20200828085622.8365-6-chenyi.qiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM supports the nested VM_{EXIT, ENTRY}_LOAD_IA32_PERF_GLOBAL_CTRL and
VM_{ENTRY_LOAD, EXIT_CLEAR}_BNDCFGS, but they are not exposed by the
system ioctl KVM_GET_MSR. Add them to the setup of nested VMX controls MSR.
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20200828085622.8365-2-chenyi.qiang@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The save and ctl pointers are passed uninitialized to kfree() when
svm_set_nested_state() follows the 'goto out_set_gif' path. While the
issue could've been fixed by initializing these on-stack varialbles to
NULL, it seems preferable to eliminate 'out_set_gif' label completely as
it is not actually a failure path and duplicating a single svm_set_gif()
call doesn't look too bad.
[ bp: Drop obscure Addresses-Coverity: tag. ]
Fixes: 6ccbd29ade ("KVM: SVM: nested: Don't allocate VMCB structures on stack")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Joerg Roedel <jroedel@suse.de>
Reported-by: Colin King <colin.king@canonical.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20200914133725.650221-1-vkuznets@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Build the kernel with `C=2`:
arch/powerpc/kvm/book3s_hv_nested.c:572:25: warning: symbol
'kvmhv_alloc_nested' was not declared. Should it be static?
arch/powerpc/kvm/book3s_64_mmu_radix.c:350:6: warning: symbol
'kvmppc_radix_set_pte_at' was not declared. Should it be static?
arch/powerpc/kvm/book3s_hv.c:3568:5: warning: symbol
'kvmhv_p9_guest_entry' was not declared. Should it be static?
arch/powerpc/kvm/book3s_hv_rm_xics.c:767:15: warning: symbol 'eoi_rc'
was not declared. Should it be static?
arch/powerpc/kvm/book3s_64_vio_hv.c:240:13: warning: symbol
'iommu_tce_kill_rm' was not declared. Should it be static?
arch/powerpc/kvm/book3s_64_vio.c:492:6: warning: symbol
'kvmppc_tce_iommu_do_map' was not declared. Should it be static?
arch/powerpc/kvm/book3s_pr.c:572:6: warning: symbol 'kvmppc_set_pvr_pr'
was not declared. Should it be static?
Those symbols are used only in the files that define them so make them
static to fix the warnings.
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The variable ret is being initialized with '-ENOMEM' that is meaningless.
So remove it.
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
diag318 code was merged in 5.9-rc1, let us add some
missing documentation
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Merge tag 'kvm-s390-master-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master
KVM: s390: add documentation for KVM_CAP_S390_DIAG318
diag318 code was merged in 5.9-rc1, let us add some
missing documentation
The commit 0f99022210 ("KVM: Check the allocation of pv cpu mask") we
have in 5.9-rc5 has two issue:
1) Compilation fails for !CONFIG_SMP, see:
https://bugzilla.kernel.org/show_bug.cgi?id=209285
2) This commit completely disables PV TLB flush, see
https://lore.kernel.org/kvm/87y2lrnnyf.fsf@vitty.brq.redhat.com/
The allocation problem is likely a theoretical one, if we don't
have memory that early in boot process we're likely doomed anyway.
Let's solve it properly later.
This reverts commit 0f99022210.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that kvm_vcpu_trap_is_write_fault() checks for S1PTW, there
is no need for kvm_vcpu_dabt_iswrite() to do the same thing, as
we already check for this condition on all existing paths.
Drop the check and add a comment instead.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200915104218.1284701-3-maz@kernel.org
KVM currently assumes that an instruction abort can never be a write.
This is in general true, except when the abort is triggered by
a S1PTW on instruction fetch that tries to update the S1 page tables
(to set AF, for example).
This can happen if the page tables have been paged out and brought
back in without seeing a direct write to them (they are thus marked
read only), and the fault handling code will make the PT executable(!)
instead of writable. The guest gets stuck forever.
In these conditions, the permission fault must be considered as
a write so that the Stage-1 update can take place. This is essentially
the I-side equivalent of the problem fixed by 60e21a0ef5 ("arm64: KVM:
Take S1 walks into account when determining S2 write faults").
Update kvm_is_write_fault() to return true on IABT+S1PTW, and introduce
kvm_vcpu_trap_is_exec_fault() that only return true when no faulting
on a S1 fault. Additionally, kvm_vcpu_dabt_iss1tw() is renamed to
kvm_vcpu_abt_iss1tw(), as the above makes it plain that it isn't
specific to data abort.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Will Deacon <will@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200915104218.1284701-2-maz@kernel.org
POWER8 and POWER9 machines have a hardware deviation where generation
of a hypervisor decrementer exception is suppressed if the HDICE bit
in the LPCR register is 0 at the time when the HDEC register
decrements from 0 to -1. When entering a guest, KVM first writes the
HDEC register with the time until it wants the CPU to exit the guest,
and then writes the LPCR with the guest value, which includes
HDICE = 1. If HDEC decrements from 0 to -1 during the interval
between those two events, it is possible that we can enter the guest
with HDEC already negative but no HDEC exception pending, meaning that
no HDEC interrupt will occur while the CPU is in the guest, or at
least not until HDEC wraps around. Thus it is possible for the CPU to
keep executing in the guest for a long time; up to about 4 seconds on
POWER8, or about 4.46 years on POWER9 (except that the host kernel
hard lockup detector will fire first).
To fix this, we set the LPCR[HDICE] bit before writing HDEC on guest
entry.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The current nested KVM code does not support HPT guests. This is
informed/enforced in some ways:
- Hosts < P9 will not be able to enable the nested HV feature;
- The nested hypervisor MMU capabilities will not contain
KVM_CAP_PPC_MMU_HASH_V3;
- QEMU reflects the MMU capabilities in the
'ibm,arch-vec-5-platform-support' device-tree property;
- The nested guest, at 'prom_parse_mmu_model' ignores the
'disable_radix' kernel command line option if HPT is not supported;
- The KVM_PPC_CONFIGURE_V3_MMU ioctl will fail if trying to use HPT.
There is, however, still a way to start a HPT guest by using
max-compat-cpu=power8 at the QEMU machine options. This leads to the
guest being set to use hash after QEMU calls the KVM_PPC_ALLOCATE_HTAB
ioctl.
With the guest set to hash, the nested hypervisor goes through the
entry path that has no knowledge of nesting (kvmppc_run_vcpu) and
crashes when it tries to execute an hypervisor-privileged (mtspr
HDEC) instruction at __kvmppc_vcore_entry:
root@L1:~ $ qemu-system-ppc64 -machine pseries,max-cpu-compat=power8 ...
<snip>
[ 538.543303] CPU: 83 PID: 25185 Comm: CPU 0/KVM Not tainted 5.9.0-rc4 #1
[ 538.543355] NIP: c00800000753f388 LR: c00800000753f368 CTR: c0000000001e5ec0
[ 538.543417] REGS: c0000013e91e33b0 TRAP: 0700 Not tainted (5.9.0-rc4)
[ 538.543470] MSR: 8000000002843033 <SF,VEC,VSX,FP,ME,IR,DR,RI,LE> CR: 22422882 XER: 20040000
[ 538.543546] CFAR: c00800000753f4b0 IRQMASK: 3
GPR00: c0080000075397a0 c0000013e91e3640 c00800000755e600 0000000080000000
GPR04: 0000000000000000 c0000013eab19800 c000001394de0000 00000043a054db72
GPR08: 00000000003b1652 0000000000000000 0000000000000000 c0080000075502e0
GPR12: c0000000001e5ec0 c0000007ffa74200 c0000013eab19800 0000000000000008
GPR16: 0000000000000000 c00000139676c6c0 c000000001d23948 c0000013e91e38b8
GPR20: 0000000000000053 0000000000000000 0000000000000001 0000000000000000
GPR24: 0000000000000001 0000000000000001 0000000000000000 0000000000000001
GPR28: 0000000000000001 0000000000000053 c0000013eab19800 0000000000000001
[ 538.544067] NIP [c00800000753f388] __kvmppc_vcore_entry+0x90/0x104 [kvm_hv]
[ 538.544121] LR [c00800000753f368] __kvmppc_vcore_entry+0x70/0x104 [kvm_hv]
[ 538.544173] Call Trace:
[ 538.544196] [c0000013e91e3640] [c0000013e91e3680] 0xc0000013e91e3680 (unreliable)
[ 538.544260] [c0000013e91e3820] [c0080000075397a0] kvmppc_run_core+0xbc8/0x19d0 [kvm_hv]
[ 538.544325] [c0000013e91e39e0] [c00800000753d99c] kvmppc_vcpu_run_hv+0x404/0xc00 [kvm_hv]
[ 538.544394] [c0000013e91e3ad0] [c0080000072da4fc] kvmppc_vcpu_run+0x34/0x48 [kvm]
[ 538.544472] [c0000013e91e3af0] [c0080000072d61b8] kvm_arch_vcpu_ioctl_run+0x310/0x420 [kvm]
[ 538.544539] [c0000013e91e3b80] [c0080000072c7450] kvm_vcpu_ioctl+0x298/0x778 [kvm]
[ 538.544605] [c0000013e91e3ce0] [c0000000004b8c2c] sys_ioctl+0x1dc/0xc90
[ 538.544662] [c0000013e91e3dc0] [c00000000002f9a4] system_call_exception+0xe4/0x1c0
[ 538.544726] [c0000013e91e3e20] [c00000000000d140] system_call_common+0xf0/0x27c
[ 538.544787] Instruction dump:
[ 538.544821] f86d1098 60000000 60000000 48000099 e8ad0fe8 e8c500a0 e9264140 75290002
[ 538.544886] 7d1602a6 7cec42a6 40820008 7d0807b4 <7d164ba6> 7d083a14 f90d10a0 480104fd
[ 538.544953] ---[ end trace 74423e2b948c2e0c ]---
This patch makes the KVM_PPC_ALLOCATE_HTAB ioctl fail when running in
the nested hypervisor, causing QEMU to abort.
Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
ENOTSUPP is a linux only thingy, the value of which is unknown to
userspace, not to be confused with ENOTSUP which linux maps to
EOPNOTSUPP, as permitted by POSIX [1]:
[EOPNOTSUPP]
Operation not supported on socket. The type of socket (address family
or protocol) does not support the requested operation. A conforming
implementation may assign the same values for [EOPNOTSUPP] and [ENOTSUP].
Return -EOPNOTSUPP instead of -ENOTSUPP for the following ioctls:
- KVM_GET_FPU for Book3s and BookE
- KVM_SET_FPU for Book3s and BookE
- KVM_GET_DIRTY_LOG for BookE
This doesn't affect QEMU which doesn't call the KVM_GET_FPU and
KVM_SET_FPU ioctls on POWER anyway since they are not supported,
and _buggily_ ignores anything but -EPERM for KVM_GET_DIRTY_LOG.
[1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html
Signed-off-by: Greg Kurz <groug@kaod.org>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Don't ignore return values in rsm_load_state_64/32 to avoid
loading invalid state from SMM state area if it was tampered with
by the guest.
This is primarly intended to avoid letting guest set bits in EFER
(like EFER.SVME when nesting is disabled) by manipulating SMM save area.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827171145.374620-8-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* check that guest is 64 bit guest, otherwise the SVM related fields
in the smm state area are not defined
* If the SMM area indicates that SMM interrupted a running guest,
check that EFER.SVME which is also saved in this area is set, otherwise
the guest might have tampered with SMM save area, and so indicate
emulation failure which should triple fault the guest.
* Check that that guest CPUID supports SVM (due to the same issue as above)
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827162720.278690-4-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This code was missing and was forcing the L2 run with L1's msr
permission bitmap
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827162720.278690-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently code in svm_set_nested_state copies the current vmcb control
area to L1 control area (hsave->control), under assumption that
it mostly reflects the defaults that kvm choose, and later qemu
overrides these defaults with L2 state using standard KVM interfaces,
like KVM_SET_REGS.
However nested GIF (which is AMD specific thing) is by default is true,
and it is copied to hsave area as such.
This alone is not a big deal since on VMexit, GIF is always set to false,
regardless of what it was on VM entry. However in nested_svm_vmexit we
were first were setting GIF to false, but then we overwrite the control
fields with value from the hsave area. (including the nested GIF field
itself if GIF virtualization is enabled).
Now on normal vm entry this is not a problem, since GIF is usually false
prior to normal vm entry, and this is the value that copied to hsave,
and then restored, but this is not always the case when the nested state
is loaded as explained above.
To fix this issue, move svm_set_gif after we restore the L1 control
state in nested_svm_vmexit, so that even with wrong GIF in the
saved L1 control area, we still clear GIF as the spec says.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827162720.278690-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
