To enable proper debug register emulation under all conditions, trap
access to all DR0..7. This may be optimized later on.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Enhance mov dr instruction emulation used by SVM so that it properly
handles dr4/5: alias to dr6/7 if cr4.de is cleared. Otherwise return
EMULATE_FAIL which will let our only possible caller in that scenario,
ud_interception, re-inject UD.

We do not need to inject faults, SVM does this for us (exceptions take
precedence over instruction interceptions). For the same reason, the
value overflow checks can be removed.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Now that we can allow the guest to play with cr0 when the fpu is loaded,
we can enable lazy fpu when npt is in use.
Acked-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If two conditions apply:
 - no bits outside TS and EM differ between the host and guest cr0
 - the fpu is active

then we can activate the selective cr0 write intercept and drop the
unconditional cr0 read and write intercept, and allow the guest to run
with the host fpu state.  This reduces cr0 exits due to guest fpu management
while the guest fpu is loaded.
Acked-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Currently we don't intercept cr0 at all when npt is enabled.  This improves
performance but requires us to activate the fpu at all times.

Remove this behaviour in preparation for adding selective cr0 intercepts.
Acked-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

init_vmcb() sets up the intercepts as if the fpu is active, so initialize it
there.  This avoids an INIT from setting up intercepts inconsistent with
fpu_active.
Acked-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Defer fpu deactivation as much as possible - if the guest fpu is loaded, keep
it loaded until the next heavyweight exit (where we are forced to unload it).
This reduces unnecessary exits.

We also defer fpu activation on clts; while clts signals the intent to use the
fpu, we can't be sure the guest will actually use it.
Signed-off-by: NAvi Kivity <avi@redhat.com>

We will use this later to give the guest ownership of cr0.ts.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Since we'd like to allow the guest to own a few bits of cr0 at times, we need
to know when we access those bits.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Then the callback can provide the maximum supported large page level, which
is more flexible.

Also move the gb page support into x86_64 specific.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The tsc_offset adjustment in svm_vcpu_load is executed
unconditionally even if Linux considers the host tsc as
stable. This causes a Linux guest detecting an unstable tsc
in any case.
This patch removes the tsc_offset adjustment if the host tsc
is stable. The guest will now get the benefit of a stable
tsc too.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Before enabling, execution of "rdtscp" in guest would result in #UD.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Sometime, we need to adjust some state in order to reflect guest CPUID
setting, e.g. if we don't expose rdtscp to guest, we won't want to enable
it on hardware. cpuid_update() is introduced for this purpose.

Also export kvm_find_cpuid_entry() for later use.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This new IOCTL exports all yet user-invisible states related to
exceptions, interrupts, and NMIs. Together with appropriate user space
changes, this fixes sporadic problems of vmsave/restore, live migration
and system reset.

[avi: future-proof abi by adding a flags field]
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The svm_set_cr0() call will initialize save->cr0 properly even when npt is
enabled, clearing the NW and CD bits as expected, so we don't need to
initialize it manually for npt_enabled anymore.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

svm_vcpu_reset() was not properly resetting the contents of the guest-visible
cr0 register, causing the following issue:
https://bugzilla.redhat.com/show_bug.cgi?id=525699

Without resetting cr0 properly, the vcpu was running the SIPI bootstrap routine
with paging enabled, making the vcpu get a pagefault exception while trying to
run it.

Instead of setting vmcb->save.cr0 directly, the new code just resets
kvm->arch.cr0 and calls kvm_set_cr0(). The bits that were set/cleared on
vmcb->save.cr0 (PG, WP, !CD, !NW) will be set properly by svm_set_cr0().

kvm_set_cr0() is used instead of calling svm_set_cr0() directly to make sure
kvm_mmu_reset_context() is called to reset the mmu to nonpaging mode.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Push the NMI-related singlestep variable into vcpu_svm. It's dealing
with an AMD-specific deficit, nothing generic for x86.
Acked-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>

 arch/x86/include/asm/kvm_host.h |    1 -
 arch/x86/kvm/svm.c              |   12 +++++++-----
 2 files changed, 7 insertions(+), 6 deletions(-)
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

New AMD processors (Family 0x10 models 8+) support the Pause
Filter Feature.  This feature creates a new field in the VMCB
called Pause Filter Count.  If Pause Filter Count is greater
than 0 and intercepting PAUSEs is enabled, the processor will
increment an internal counter when a PAUSE instruction occurs
instead of intercepting.  When the internal counter reaches the
Pause Filter Count value, a PAUSE intercept will occur.

This feature can be used to detect contended spinlocks,
especially when the lock holding VCPU is not scheduled.
Rescheduling another VCPU prevents the VCPU seeking the
lock from wasting its quantum by spinning idly.

Experimental results show that most spinlocks are held
for less than 1000 PAUSE cycles or more than a few
thousand.  Default the Pause Filter Counter to 3000 to
detect the contended spinlocks.

Processor support for this feature is indicated by a CPUID
bit.

On a 24 core system running 4 guests each with 16 VCPUs,
this patch improved overall performance of each guest's
32 job kernbench by approximately 3-5% when combined
with a scheduler algorithm thati caused the VCPU to
sleep for a brief period. Further performance improvement
may be possible with a more sophisticated yield algorithm.
Signed-off-by: NMark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

With all important informations now delivered through
tracepoints we can savely remove the nsvm_printk debugging
code for nested svm.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch adds a tracepoint for the event that the guest
executed the SKINIT instruction. This information is
important because SKINIT is an SVM extenstion not yet
implemented by nested SVM and we may need this information
for debugging hypervisors that do not yet run on nested SVM.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch adds a tracepoint for the event that the guest
executed the INVLPGA instruction.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch adds a special tracepoint for the event that a
nested #vmexit is injected because kvm wants to inject an
interrupt into the guest.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch adds a tracepoint for a nested #vmexit that gets
re-injected to the guest.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch adds a tracepoint for every #vmexit we get from a
nested guest.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch adds a dedicated kvm tracepoint for a nested
vmrun.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The nested SVM code emulates a #vmexit caused by a request
to open the irq window right in the request function. This
is a bug because the request function runs with preemption
and interrupts disabled but the #vmexit emulation might
sleep. This can cause a schedule()-while-atomic bug and is
fixed with this patch.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

If event_inj is valid on a #vmexit the host CPU would write
the contents to exit_int_info, so the hypervisor knows that
the event wasn't injected.

We don't do this in nested SVM by now which is a bug and
fixed by this patch.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Much of so far vendor-specific code for setting up guest debug can
actually be handled by the generic code. This also fixes a minor deficit
in the SVM part /wrt processing KVM_GUESTDBG_ENABLE.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Both VMX and SVM require per-cpu memory allocation, which is done at module
init time, for only online cpus.

Backend was not allocating enough structure for all possible CPUs, so
new CPUs coming online could not be hardware enabled.
Signed-off-by: NZachary Amsden <zamsden@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NZachary Amsden <zamsden@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch replaces them with native_read_tsc() which can
also be used in expressions and saves a variable on the
stack in this case.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The exit_int_info field is only written by the hardware and
never read. So it does not need to be copied on a vmrun
emulation.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This patch reorganizes the logic in svm_interrupt_allowed to
make it better to read. This is important because the logic
is a lot more complicated with Nested SVM.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

X86 CPUs need to have some magic happening to enable the virtualization
extensions on them. This magic can result in unpleasant results for
users, like blocking other VMMs from working (vmx) or using invalid TLB
entries (svm).

Currently KVM activates virtualization when the respective kernel module
is loaded. This blocks us from autoloading KVM modules without breaking
other VMMs.

To circumvent this problem at least a bit, this patch introduces on
demand activation of virtualization. This means, that instead
virtualization is enabled on creation of the first virtual machine
and disabled on destruction of the last one.

So using this, KVM can be easily autoloaded, while keeping other
hypervisors usable.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

nested_svm_map unnecessarily takes mmap_sem around gfn_to_page, since
gfn_to_page / get_user_pages are responsible for it.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Acked-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

They're just copies of vcpu->run, which is readily accessible.
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch updates percpu related symbols in x86 such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* arch/x86/kernel/cpu/common.c: rename local variable to avoid collision

* arch/x86/kvm/svm.c: s/svm_data/sd/ for local variables to avoid collision

* arch/x86/kernel/cpu/cpu_debug.c: s/cpu_arr/cpud_arr/
  				   s/priv_arr/cpud_priv_arr/
				   s/cpu_priv_count/cpud_priv_count/

* arch/x86/kernel/cpu/intel_cacheinfo.c: s/cpuid4_info/ici_cpuid4_info/
  					 s/cache_kobject/ici_cache_kobject/
					 s/index_kobject/ici_index_kobject/

* arch/x86/kernel/ds.c: s/cpu_context/cpu_ds_context/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: N(kvm) Avi Kivity <avi@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: x86@kernel.org

When running nested we need to touch the l1 guests
tsc_offset. Otherwise changes will be lost or a wrong value
be read.

Cc: stable@kernel.org
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

When svm_vcpu_load is called while the vcpu is running in
guest mode the tsc adjustment made there is lost on the next
emulated #vmexit. This causes the tsc running backwards in
the guest. This patch fixes the issue by also adjusting the
tsc_offset in the emulated hsave area so that it will not
get lost.

Cc: stable@kernel.org
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

It is no longer possible to reproduce the problem any more, so presumably
it has been fixed.
Signed-off-by: NAvi Kivity <avi@redhat.com>