This is a prep series for the mediated PMU, and for Xin's series to add
support for the immediate forms of RDMSR and WRMSRNS (I'll post a v3 of
that series on top of this).
The first half cleans up a variety of warts and flaws in the VM-Exit fastpath
handlers. The second half cleans up the PMU code related to "triggering"
instruction retired and branches retired events. The end goal of the two
halves (other than general cleanup) is to be able bail from the fastpath when
using the mediated PMU and the guest is counting instructions retired, with
minimal overhead, e.g. without having to acquire SRCU.
Because the mediated PMU context switches PMU state _outside_ of the fastpath,
the mediated PMU won't be able to increment PMCs in the fastpath, and so won't
be able to skip emulated instructions in the fastpath if the vCPU is counting
instructions retired.
The last patch to handle INVD in the fastpath is a bit dubious. It works just
fine, but it's dangerously close to "just because we can, doesn't mean we
should" territory. I added INVD to the fastpath before I realized that
MSR_IA32_TSC_DEADLINE could be handled in the fastpath irrespective of the
VMX preemption timer, i.e. on AMD CPUs. But being able to use INVD to test
the fastpath is still super convenient, as there are no side effects (unless
someone ran the test on bare metal :-D), no register constraints, and no
vCPU model requirements. So, I kept it, because I couldn't come up with a
good reason not to.
Sean Christopherson (18):
KVM: SVM: Skip fastpath emulation on VM-Exit if next RIP isn't valid
KVM: x86: Add kvm_icr_to_lapic_irq() helper to allow for fastpath IPIs
KVM: x86: Only allow "fast" IPIs in fastpath WRMSR(X2APIC_ICR) handler
KVM: x86: Drop semi-arbitrary restrictions on IPI type in fastpath
KVM: x86: Unconditionally handle MSR_IA32_TSC_DEADLINE in fastpath
exits
KVM: x86: Acquire SRCU in WRMSR fastpath iff instruction needs to be
skipped
KVM: x86: Unconditionally grab data from EDX:EAX in WRMSR fastpath
KVM: x86: Fold WRMSR fastpath helpers into the main handler
KVM: x86/pmu: Move kvm_init_pmu_capability() to pmu.c
KVM: x86/pmu: Add wrappers for counting emulated instructions/branches
KVM: x86/pmu: Calculate set of to-be-emulated PMCs at time of WRMSRs
KVM: x86/pmu: Rename pmc_speculative_in_use() to
pmc_is_locally_enabled()
KVM: x86/pmu: Open code pmc_event_is_allowed() in its callers
KVM: x86/pmu: Drop redundant check on PMC being globally enabled for
emulation
KVM: x86/pmu: Drop redundant check on PMC being locally enabled for
emulation
KVM: x86/pmu: Rename check_pmu_event_filter() to
pmc_is_event_allowed()
KVM: x86: Push acquisition of SRCU in fastpath into
kvm_pmu_trigger_event()
KVM: x86: Add a fastpath handler for INVD
arch/x86/include/asm/kvm_host.h | 3 +
arch/x86/kvm/lapic.c | 59 ++++++++----
arch/x86/kvm/lapic.h | 3 +-
arch/x86/kvm/pmu.c | 155 +++++++++++++++++++++++++-------
arch/x86/kvm/pmu.h | 60 ++-----------
arch/x86/kvm/svm/svm.c | 14 ++-
arch/x86/kvm/vmx/nested.c | 2 +-
arch/x86/kvm/vmx/pmu_intel.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 2 +
arch/x86/kvm/x86.c | 85 +++++-------------
arch/x86/kvm/x86.h | 1 +
11 files changed, 218 insertions(+), 168 deletions(-)
base-commit: 196d9e72c4b0bd68b74a4ec7f52d248f37d0f030
--
2.50.1.565.gc32cd1483b-goog
