This patch implements a workaround for AMD erratum 383 into
KVM. Without this erratum fix it is possible for a guest to
kill the host machine. This patch implements the suggested
workaround for hypervisors which will be published by the
next revision guide update.
[jan: fix overflow warning on i386]
[xiao: fix unused variable warning]
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch moves handling of the MC vmexits to an earlier
point in the vmexit. The handle_exit function is too late
because the vcpu might alreadry have changed its physical
cpu.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
* 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (269 commits)
KVM: x86: Add missing locking to arch specific vcpu ioctls
KVM: PPC: Add missing vcpu_load()/vcpu_put() in vcpu ioctls
KVM: MMU: Segregate shadow pages with different cr0.wp
KVM: x86: Check LMA bit before set_efer
KVM: Don't allow lmsw to clear cr0.pe
KVM: Add cpuid.txt file
KVM: x86: Tell the guest we'll warn it about tsc stability
x86, paravirt: don't compute pvclock adjustments if we trust the tsc
x86: KVM guest: Try using new kvm clock msrs
KVM: x86: export paravirtual cpuid flags in KVM_GET_SUPPORTED_CPUID
KVM: x86: add new KVMCLOCK cpuid feature
KVM: x86: change msr numbers for kvmclock
x86, paravirt: Add a global synchronization point for pvclock
x86, paravirt: Enable pvclock flags in vcpu_time_info structure
KVM: x86: Inject #GP with the right rip on efer writes
KVM: SVM: Don't allow nested guest to VMMCALL into host
KVM: x86: Fix exception reinjection forced to true
KVM: Fix wallclock version writing race
KVM: MMU: Don't read pdptrs with mmu spinlock held in mmu_alloc_roots
KVM: VMX: enable VMXON check with SMX enabled (Intel TXT)
...
This patch disables the possibility for a l2-guest to do a
VMMCALL directly into the host. This would happen if the
l1-hypervisor doesn't intercept VMMCALL and the l2-guest
executes this instruction.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
vmx and svm vcpus have different contents and therefore may have different
alignmment requirements. Let each specify its required alignment.
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch prevents MCE intercepts from being propagated
into the L1 guest if they happened in an L2 guest.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds logic to kvm/x86 which allows to mark an
injected exception as reinjected. This allows to remove an
ugly hack from svm_complete_interrupts that prevented
exceptions from being reinjected at all in the nested case.
The hack was necessary because an reinjected exception into
the nested guest could cause a nested vmexit emulation. But
reinjected exceptions must not intercept. The downside of
the hack is that a exception that in injected could get
lost.
This patch fixes the problem and puts the code for it into
generic x86 files because. Nested-VMX will likely have the
same problem and could reuse the code.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the reporting of the emulated SVM
features to userspace instead of the real hardware
capabilities. Every real hardware capability needs emulation
in nested svm so the old behavior was broken.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the get_supported_cpuid callback to
kvm_x86_ops. It will be used in do_cpuid_ent to delegate the
decission about some supported cpuid bits to the
architecture modules.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements propagation of a failes guest vmrun
back into the guest instead of killing the whole guest.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch syncs cr0 and cr3 from the vmcb to the kvm state
before nested intercept handling is done. This allows to
simplify the vmexit path.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch fixes a bug where a nested guest always went over
the same instruction because the rip was not advanced on a
nested vmexit.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The patch introducing nested nmi handling had a bug. The
check does not belong to enable_nmi_window but must be in
nmi_allowed. This patch fixes this.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If kvm_task_switch() fails code exits to userspace without specifying
exit reason, so the previous exit reason is reused by userspace. Fix
this by specifying exit reason correctly.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When a fault triggers a task switch, the error code, if existent, has to
be pushed on the new task's stack. Implement the missing bits.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently both SVM and VMX have their own DR handling code. Move it to
x86.c.
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
On SVM we set the instruction length of skipped instructions
to hard-coded, well known values, which could be wrong when (bogus,
but valid) prefixes (REX, segment override) are used.
Newer AMD processors (Fam10h 45nm and better, aka. PhenomII or
AthlonII) have an explicit NEXTRIP field in the VMCB containing the
desired information.
Since it is cheap to do so, we use this field to override the guessed
value on newer processors.
A fix for older CPUs would be rather expensive, as it would require
to fetch and partially decode the instruction. As the problem is not
a security issue and needs special, handcrafted code to trigger
(no compiler will ever generate such code), I omit a fix for older
CPUs.
If someone is interested, I have both a patch for these CPUs as well as
demo code triggering this issue: It segfaults under KVM, but runs
perfectly on native Linux.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
in/out emulation is broken now. The breakage is different depending
on where IO device resides. If it is in userspace emulator reports
emulation failure since it incorrectly interprets kvm_emulate_pio()
return value. If IO device is in the kernel emulation of 'in' will do
nothing since kvm_emulate_pio() stores result directly into vcpu
registers, so emulator will overwrite result of emulation during
commit of shadowed register.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Reading rip is expensive on vmx, so move it inside the tracepoint so we only
incur the cost if tracing is enabled.
Signed-off-by: Avi Kivity <avi@redhat.com>
These bits are ignored by the hardware too. Implement this
for nested svm too.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch adds the correct handling of the nested io
permission bitmap. Old behavior was to not lookup the port
in the iopm but only reinject an io intercept to the guest.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
There is a generic function now to calculate msrpm offsets.
Use that function in nested_svm_exit_handled_msr() remove
the duplicate logic (which had a bug anyway).
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch optimizes the way the msrpm of the host and the
guest are merged. The old code merged the 2 msrpm pages
completly. This code needed to touch 24kb of memory for that
operation. The optimized variant this patch introduces
merges only the parts where the host msrpm may contain zero
bits. This reduces the amount of memory which is touched to
48 bytes.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch introduces a list with all msrs a guest might
have direct access to and changes the svm_vcpu_init_msrpm
function to use this list.
It also adds a check to set_msr_interception which triggers
a warning if a developer changes a msr intercept that is not
in the list.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The algorithm to find the offset in the msrpm for a given
msr is needed at other places too. Move that logic to its
own function.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The nested_svm_exit_handled_msr() returned an bool which is
a bug. I worked by accident because the exected integer
return values match with the true and false values. This
patch changes the return value to int and let the function
return the correct values.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch makes KVM on 32 bit SVM working again by
correcting the masks used for iret interception. With the
wrong masks the upper 32 bits of the intercepts are masked
out which leaves vmrun unintercepted. This is not legal on
svm and the vmrun fails.
Bug was introduced by commits 95ba827313 and 3cfc3092.
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Linux now has native_store_gdt() to do the same. Use it instead of
kvm local version.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When injecting an vmexit.intr into the nested hypervisor
there might be leftover values in the exit_info fields.
Clear them to not confuse nested hypervisors.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If we have the following situation with nested svm:
1. Host KVM intercepts cr0 writes
2. Guest hypervisor intercepts only selective cr0 writes
Then we get an cr0 write intercept which is handled on the
host. But that intercepts may actually be a selective cr0
intercept for the guest. This patch checks for this
condition and injects a selective cr0 intercept if needed.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the emulation of the vm_cr msr for
nested svm.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds a tracepoint to get information about the
most important intercept bitmasks from the nested vmcb.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
A recent change broke tracing of the nested vmcb address. It
was reported as 0 all the time. This patch fixes it.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the NMI intercept checking for nested
svm.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Without resetting the MMU the gva_to_pga function will not
work reliably when the vcpu is running in nested context.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch removes whitespace errors, fixes comment formats
and most of checkpatch warnings. Now vim does not show
c-space-errors anymore.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When in guest debugging mode, we have to reinject those #BP software
exceptions that are caused by guest-injected INT3. As older AMD
processors do not support the required nRIP VMCB field, try to emulate
it by moving RIP past the instruction on exception injection. Fix it up
again in case the injection failed and we were able to catch this. This
does not work for unintercepted faults, but it is better than doing
nothing.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Move svm_queue_exception past skip_emulated_instruction to allow calling
it later on.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The interrupt shadow created by STI or MOV-SS-like operations is part of
the VCPU state and must be preserved across migration. Transfer it in
the spare padding field of kvm_vcpu_events.interrupt.
As a side effect we now have to make vmx_set_interrupt_shadow robust
against both shadow types being set. Give MOV SS a higher priority and
skip STI in that case to avoid that VMX throws a fault on next entry.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The nested_svm_intr() function does not execute the vmexit
anymore. Therefore we may still be in the nested state after
that function ran. This patch changes the nested_svm_intr()
function to return wether the irq window could be enabled.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The new lazy fpu switching code may disable cr0 intercepts
when running nested. This is a bug because the nested
hypervisor may still want to intercept cr0 which will break
in this situation. This patch fixes this issue and makes
lazy fpu switching working with nested svm.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Certain functions called during the emulated world switch
behave differently when the vcpu is running nested. This is
not the expected behavior during a world switch emulation.
This patch ensures that the nested state is activated only
if the vcpu is completly in nested state.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch makes syncing of the guest tpr to the lapic
conditional on !nested. Otherwise a nested guest using the
TPR could freeze the guest.
Another important change this patch introduces is that the
cr8 intercept bits are no longer ORed at vmrun emulation if
the guest sets VINTR_MASKING in its VMCB. The reason is that
nested cr8 accesses need alway be handled by the nested
hypervisor because they change the shadow version of the
tpr.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The nested_svm_exit_handled_msr() function maps only one
page of the guests msr permission bitmap. This patch changes
the code to use kvm_read_guest to fix the bug.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The nested_svm_map() function can sleep and must not be
called from atomic context. So annotate that function.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently the vmexit emulation does not sync control
registers were the access is typically intercepted by the
nested hypervisor. But we can not count on that intercepts
to sync these registers too and make the code
architecturally more correct.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Move the actual vmexit routine out of code that runs with
irqs and preemption disabled.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Use of kmap_atomic disables preemption but if we run in
shadow-shadow mode the vmrun emulation executes kvm_set_cr3
which might sleep or fault. So use kmap instead for
nested_svm_map.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
x86 arch defines desc_ptr for idt/gdt pointers, no need to define
another structure in kvm code.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
svm_create_vcpu() does not free the pages allocated during the creation
when it fails to complete the allocations. This patch fixes it.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
