Remove an unused struct x86_emulate_ctxt * param from low level helpers
used to access guest FPU state. The unused param was left behind by
commit 6ab0b9feb8 ("x86,kvm: remove KVM emulator get_fpu / put_fpu").
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reload the current thread's FPU state, which contains the guest's FPU
state, to the CPU registers if necessary during vcpu_enter_guest().
TIF_NEED_FPU_LOAD can be set any time control is transferred out of KVM,
e.g. if I/O is triggered during a KVM call to get_user_pages() or if a
softirq occurs while KVM is scheduled in.
Moving the handling of TIF_NEED_FPU_LOAD from vcpu_enter_guest() to
kvm_arch_vcpu_load(), effectively kvm_sched_in(), papered over a bug
where kvm_put_guest_fpu() failed to account for TIF_NEED_FPU_LOAD. The
easiest way to the kvm_put_guest_fpu() bug was to run with involuntary
preemption enable, thus handling TIF_NEED_FPU_LOAD during kvm_sched_in()
made the bug go away. But, removing the handling in vcpu_enter_guest()
exposed KVM to the rare case of a softirq triggering kernel_fpu_begin()
between vcpu_load() and vcpu_enter_guest().
Now that kvm_{load,put}_guest_fpu() correctly handle TIF_NEED_FPU_LOAD,
revert the commit to both restore the vcpu_enter_guest() behavior and
eliminate the superfluous switch_fpu_return() in kvm_arch_vcpu_load().
Note, leaving the handling in kvm_arch_vcpu_load() isn't wrong per se,
but it is unnecessary, and most critically, makes it extremely difficult
to find bugs such as the kvm_put_guest_fpu() issue due to shrinking the
window where a softirq can corrupt state.
A sample trace triggered by warning if TIF_NEED_FPU_LOAD is set while
vcpu state is loaded:
<IRQ>
gcmaes_crypt_by_sg.constprop.12+0x26e/0x660
? 0xffffffffc024547d
? __qdisc_run+0x83/0x510
? __dev_queue_xmit+0x45e/0x990
? ip_finish_output2+0x1a8/0x570
? fib4_rule_action+0x61/0x70
? fib4_rule_action+0x70/0x70
? fib_rules_lookup+0x13f/0x1c0
? helper_rfc4106_decrypt+0x82/0xa0
? crypto_aead_decrypt+0x40/0x70
? crypto_aead_decrypt+0x40/0x70
? crypto_aead_decrypt+0x40/0x70
? esp_output_tail+0x8f4/0xa5a [esp4]
? skb_ext_add+0xd3/0x170
? xfrm_input+0x7a6/0x12c0
? xfrm4_rcv_encap+0xae/0xd0
? xfrm4_transport_finish+0x200/0x200
? udp_queue_rcv_one_skb+0x1ba/0x460
? udp_unicast_rcv_skb.isra.63+0x72/0x90
? __udp4_lib_rcv+0x51b/0xb00
? ip_protocol_deliver_rcu+0xd2/0x1c0
? ip_local_deliver_finish+0x44/0x50
? ip_local_deliver+0xe0/0xf0
? ip_protocol_deliver_rcu+0x1c0/0x1c0
? ip_rcv+0xbc/0xd0
? ip_rcv_finish_core.isra.19+0x380/0x380
? __netif_receive_skb_one_core+0x7e/0x90
? netif_receive_skb_internal+0x3d/0xb0
? napi_gro_receive+0xed/0x150
? 0xffffffffc0243c77
? net_rx_action+0x149/0x3b0
? __do_softirq+0xe4/0x2f8
? handle_irq_event_percpu+0x6a/0x80
? irq_exit+0xe6/0xf0
? do_IRQ+0x7f/0xd0
? common_interrupt+0xf/0xf
</IRQ>
? irq_entries_start+0x20/0x660
? vmx_get_interrupt_shadow+0x2f0/0x710 [kvm_intel]
? kvm_set_msr_common+0xfc7/0x2380 [kvm]
? recalibrate_cpu_khz+0x10/0x10
? ktime_get+0x3a/0xa0
? kvm_arch_vcpu_ioctl_run+0x107/0x560 [kvm]
? kvm_init+0x6bf/0xd00 [kvm]
? __seccomp_filter+0x7a/0x680
? do_vfs_ioctl+0xa4/0x630
? security_file_ioctl+0x32/0x50
? ksys_ioctl+0x60/0x90
? __x64_sys_ioctl+0x16/0x20
? do_syscall_64+0x5f/0x1a0
? entry_SYSCALL_64_after_hwframe+0x44/0xa9
---[ end trace 9564a1ccad733a90 ]---
This reverts commit e751732486.
Fixes: e751732486 ("KVM: X86: Fix fpu state crash in kvm guest")
Reported-by: Derek Yerger <derek@djy.llc>
Reported-by: kernel@najdan.com
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Thomas Lambertz <mail@thomaslambertz.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Lock the FPU regs and reload the current thread's FPU state, which holds
the guest's FPU state, to the CPU registers if necessary prior to
accessing guest FPU state as part of emulation. kernel_fpu_begin() can
be called from softirq context, therefore KVM must ensure softirqs are
disabled (locking the FPU regs disables softirqs) when touching CPU FPU
state.
Note, for all intents and purposes this reverts commit 6ab0b9feb8
("x86,kvm: remove KVM emulator get_fpu / put_fpu"), but at the time it
was applied, removing get/put_fpu() was correct. The re-introduction
of {get,put}_fpu() is necessitated by the deferring of FPU state load.
Fixes: 5f409e20b7 ("x86/fpu: Defer FPU state load until return to userspace")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Handle TIF_NEED_FPU_LOAD similar to how fpu__copy() handles the flag
when duplicating FPU state to a new task struct. TIF_NEED_FPU_LOAD can
be set any time control is transferred out of KVM, be it voluntarily,
e.g. if I/O is triggered during a KVM call to get_user_pages, or
involuntarily, e.g. if softirq runs after an IRQ occurs. Therefore,
KVM must account for TIF_NEED_FPU_LOAD whenever it is (potentially)
accessing CPU FPU state.
Fixes: 5f409e20b7 ("x86/fpu: Defer FPU state load until return to userspace")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This reverts commit 95145c25a7.
The next few patches will fix the issue so the warning is not
needed anymore; revert it separately to simplify application to
stable kernels.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Short-circuit kvm_apic_accept_pic_intr() when pic intr is accepted, there
is no need to proceed further. Also remove unnecessary var r.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The exception pending event is cleared by kvm_clear_exception_queue(). We
shouldn't clear it again.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes Spectre-v1/L1TF vulnerabilities in intel_find_fixed_event()
and intel_rdpmc_ecx_to_pmc().
kvm_rdpmc() (ancestor of intel_find_fixed_event()) and
reprogram_fixed_counter() (ancestor of intel_rdpmc_ecx_to_pmc()) are
exported symbols so KVM should treat them conservatively from a security
perspective.
Fixes: 25462f7f52 ("KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in __kvm_set_dr() and
kvm_get_dr().
Both kvm_get_dr() and kvm_set_dr() (a wrapper of __kvm_set_dr()) are
exported symbols so KVM should tream them conservatively from a security
perspective.
Fixes: 020df0794f ("KVM: move DR register access handling into generic code")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in vmx_handle_exit().
While exit_reason is set by the hardware and therefore should not be
attacker-influenced, an unknown exit_reason could potentially be used to
perform such an attack.
Fixes: 55d2375e58 ("KVM: nVMX: Move nested code to dedicated files")
Signed-off-by: Marios Pomonis <pomonis@google.com>
Signed-off-by: Nick Finco <nifi@google.com>
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes Spectre-v1/L1TF vulnerabilities in
vmx_read_guest_seg_selector(), vmx_read_guest_seg_base(),
vmx_read_guest_seg_limit() and vmx_read_guest_seg_ar(). When
invoked from emulation, these functions contain index computations
based on the (attacker-influenced) segment value. Using constants
prevents the attack.
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in set_msr_mce() and
get_msr_mce().
Both functions contain index computations based on the
(attacker-controlled) MSR number.
Fixes: 890ca9aefa ("KVM: Add MCE support")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in the get_gp_pmc() and
get_fixed_pmc() functions.
They both contain index computations based on the (attacker-controlled)
MSR number.
Fixes: 25462f7f52 ("KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in fixed_msr_to_seg_unit().
This function contains index computations based on the
(attacker-controlled) MSR number.
Fixes: de9aef5e1a ("KVM: MTRR: introduce fixed_mtrr_segment table")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in kvm_lapic_reg_write().
This function contains index computations based on the
(attacker-controlled) MSR number.
Fixes: 0105d1a526 ("KVM: x2apic interface to lapic")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in ioapic_write_indirect().
This function contains index computations based on the
(attacker-controlled) IOREGSEL register.
This patch depends on patch
"KVM: x86: Protect ioapic_read_indirect() from Spectre-v1/L1TF attacks".
Fixes: 70f93dae32 ("KVM: Use temporary variable to shorten lines.")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in ioapic_read_indirect().
This function contains index computations based on the
(attacker-controlled) IOREGSEL register.
Fixes: a2c118bfab ("KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in picdev_write().
It replaces index computations based on the (attacked-controlled) port
number with constants through a minor refactoring.
Fixes: 85f455f7dd ("KVM: Add support for in-kernel PIC emulation")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes Spectre-v1/L1TF vulnerabilities in kvm_hv_msr_get_crash_data()
and kvm_hv_msr_set_crash_data().
These functions contain index computations that use the
(attacker-controlled) MSR number.
Fixes: e7d9513b60 ("kvm/x86: added hyper-v crash msrs into kvm hyperv context")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes a Spectre-v1/L1TF vulnerability in x86_decode_insn().
kvm_emulate_instruction() (an ancestor of x86_decode_insn()) is an exported
symbol, so KVM should treat it conservatively from a security perspective.
Fixes: 045a282ca4 ("KVM: emulator: implement fninit, fnstsw, fnstcw")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Current SVM implementation does not have support for handling PKU. Guests
running on a host with future AMD cpus that support the feature will read
garbage from the PKRU register and will hit segmentation faults on boot as
memory is getting marked as protected that should not be. Ensure that cpuid
from SVM does not advertise the feature.
Signed-off-by: John Allen <john.allen@amd.com>
Cc: stable@vger.kernel.org
Fixes: 0556cbdc2f ("x86/pkeys: Don't check if PKRU is zero before writing it")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit() now that all
arch specific implementations are nops.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fold init() into create() now that the two are called back-to-back by
common KVM code (kvm_vcpu_init() calls kvm_arch_vcpu_init() as its last
action, and kvm_vm_ioctl_create_vcpu() calls kvm_arch_vcpu_create()
immediately thereafter). This paves the way for removing
kvm_arch_vcpu_init() entirely.
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove kvm_arch_vcpu_setup() now that all arch specific implementations
are nops.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fold setup() into create() now that the two are called back-to-back by
common KVM code. This paves the way for removing kvm_arch_vcpu_setup().
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that all architectures tightly couple vcpu allocation/free with the
mandatory calls to kvm_{un}init_vcpu(), move the sequences verbatim to
common KVM code.
Move both allocation and initialization in a single patch to eliminate
thrash in arch specific code. The bisection benefits of moving the two
pieces in separate patches is marginal at best, whereas the odds of
introducing a transient arch specific bug are non-zero.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add kvm_vcpu_destroy() and wire up all architectures to call the common
function instead of their arch specific implementation. The common
destruction function will be used by future patches to move allocation
and initialization of vCPUs to common KVM code, i.e. to free resources
that are allocated by arch agnostic code.
No functional change intended.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the call to kvm_vcpu_uninit() in kvm_arch_vcpu_destroy() down a few
lines so that it is invoked immediately prior to freeing the vCPU. This
paves the way for moving the uninit and free sequence to common KVM code
without an associated functional change.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a pre-allocation arch hook to handle checks that are currently done
by arch specific code prior to allocating the vCPU object. This paves
the way for moving the allocation to common KVM code.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove the superfluous kvm_arch_vcpu_free() as it is no longer called
from commmon KVM code. Note, kvm_arch_vcpu_destroy() *is* called from
common code, i.e. choosing which function to whack is not completely
arbitrary.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove a bogus clearing of apf.msr_val from kvm_arch_vcpu_destroy().
apf.msr_val is only set to a non-zero value by kvm_pv_enable_async_pf(),
which is only reachable by kvm_set_msr_common(), i.e. by writing
MSR_KVM_ASYNC_PF_EN. KVM does not autonomously write said MSR, i.e.
can only be written via KVM_SET_MSRS or KVM_RUN. Since KVM_SET_MSRS and
KVM_RUN are vcpu ioctls, they require a valid vcpu file descriptor.
kvm_arch_vcpu_destroy() is only called if KVM_CREATE_VCPU fails, and KVM
declares KVM_CREATE_VCPU successful once the vcpu fd is installed and
thus visible to userspace. Ergo, apf.msr_val cannot be non-zero when
kvm_arch_vcpu_destroy() is called.
Fixes: 344d9588a9 ("KVM: Add PV MSR to enable asynchronous page faults delivery.")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
x86 does not load its MMU until KVM_RUN, which cannot be invoked until
after vCPU creation succeeds. Given that kvm_arch_vcpu_destroy() is
called if and only if vCPU creation fails, it is impossible for the MMU
to be loaded.
Note, the bogus kvm_mmu_unload() call was added during an unrelated
refactoring of vCPU allocation, i.e. was presumably added as an
opportunstic "fix" for a perceived leak.
Fixes: fb3f0f51d9 ("KVM: Dynamically allocate vcpus")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the kvm_cpu_{un}init() calls to common x86 code as an intermediate
step to removing kvm_cpu_{un}init() altogether.
Note, VMX'x alloc_apic_access_page() and init_rmode_identity_map() are
per-VM allocations and are intentionally kept if vCPU creation fails.
They are freed by kvm_arch_destroy_vm().
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allocate the pio_data page after creating the MMU and local APIC so that
all direct memory allocations are grouped together. This allows setting
the return value to -ENOMEM prior to starting the allocations instead of
setting it in the fail path for every allocation.
The pio_data page is only consumed when KVM_RUN is invoked, i.e. moving
its allocation has no real functional impact.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The allocation of FPU structs is identical across VMX and SVM, move it
to common x86 code. Somewhat arbitrarily place the allocation so that
it resides directly above the associated initialization via fx_init(),
e.g. instead of retaining its position with respect to the overall vcpu
creation flow. Although the names names kvm_arch_vcpu_create() and
kvm_arch_vcpu_init() might suggest otherwise, x86 does not have a clean
split between 'create' and 'init'. Allocating the struct immediately
prior to the first use arguably improves readability *now*, and will
yield even bigger improvements when kvm_arch_vcpu_init() is removed in
a future patch.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move allocation of VMX and SVM vcpus to common x86. Although the struct
being allocated is technically a VMX/SVM struct, it can be interpreted
directly as a 'struct kvm_vcpu' because of the pre-existing requirement
that 'struct kvm_vcpu' be located at offset zero of the arch/vendor vcpu
struct.
Remove the message from the build-time assertions regarding placement of
the struct, as compatibility with the arch usercopy region is no longer
the sole dependent on 'struct kvm_vcpu' being at offset zero.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Capture the vcpu pointer in a local varaible and replace '&svm->vcpu'
references with a direct reference to the pointer in anticipation of
moving bits of the code to common x86 and passing the vcpu pointer into
svm_create_vcpu(), i.e. eliminate unnecessary noise from future patches.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Capture the vcpu pointer in a local varaible and replace '&vmx->vcpu'
references with a direct reference to the pointer in anticipation of
moving bits of the code to common x86 and passing the vcpu pointer into
vmx_create_vcpu(), i.e. eliminate unnecessary noise from future patches.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Do VPID allocation after calling the common kvm_vcpu_init() as a step
towards doing vCPU allocation (via kmem_cache_zalloc()) and calling
kvm_vcpu_init() back-to-back. Squishing allocation and initialization
together will eventually allow the sequence to be moved to arch-agnostic
creation code.
Note, the VPID is not consumed until KVM_RUN, slightly delaying its
allocation should have no real function impact. VPID allocation was
arbitrarily placed in the original patch, commit 2384d2b326 ("KVM:
VMX: Enable Virtual Processor Identification (VPID)").
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Free the vCPU's wbinvd_dirty_mask if vCPU creation fails after
kvm_arch_vcpu_init(), e.g. when installing the vCPU's file descriptor.
Do the freeing by calling kvm_arch_vcpu_free() instead of open coding
the freeing. This adds a likely superfluous, but ultimately harmless,
call to kvmclock_reset(), which only clears vcpu->arch.pv_time_enabled.
Using kvm_arch_vcpu_free() allows for additional cleanup in the future.
Fixes: f5f48ee15c ("KVM: VMX: Execute WBINVD to keep data consistency with assigned devices")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If the guest is configured to have SPEC_CTRL but the host does not
(which is a nonsensical configuration but these are not explicitly
forbidden) then a host-initiated MSR write can write vmx->spec_ctrl
(respectively svm->spec_ctrl) and trigger a #GP when KVM tries to
restore the host value of the MSR. Add a more comprehensive check
for valid bits of SPEC_CTRL, covering host CPUID flags and,
since we are at it and it is more correct that way, guest CPUID
flags too.
For AMD, remove the unnecessary is_guest_mode check around setting
the MSR interception bitmap, so that the code looks the same as
for Intel.
Cc: Jim Mattson <jmattson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Even if it's read-only, it can still be written to by userspace. Let
them know by adding it to KVM_GET_MSR_INDEX_LIST.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The SPTE_MMIO_MASK overlaps with the bits used to track MMIO
generation number. A high enough generation number would overwrite the
SPTE_SPECIAL_MASK region and cause the MMIO SPTE to be misinterpreted.
Likewise, setting bits 52 and 53 would also cause an incorrect generation
number to be read from the PTE, though this was partially mitigated by the
(useless if it weren't for the bug) removal of SPTE_SPECIAL_MASK from
the spte in get_mmio_spte_generation. Drop that removal, and replace
it with a compile-time assertion.
Fixes: 6eeb4ef049 ("KVM: x86: assign two bits to track SPTE kinds")
Reported-by: Ben Gardon <bgardon@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove the bogus 64-bit only condition from the check that disables MMIO
spte optimization when the system supports the max PA, i.e. doesn't have
any reserved PA bits. 32-bit KVM always uses PAE paging for the shadow
MMU, and per Intel's SDM:
PAE paging translates 32-bit linear addresses to 52-bit physical
addresses.
The kernel's restrictions on max physical addresses are limits on how
much memory the kernel can reasonably use, not what physical addresses
are supported by hardware.
Fixes: ce88decffd ("KVM: MMU: mmio page fault support")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In case writing to vmread destination operand result in a #PF, vmread
should not call nested_vmx_succeed() to set rflags to specify success.
Similar to as done in VMPTRST (See handle_vmptrst()).
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rework the handling of nEPT's bad memtype/XWR checks to micro-optimize
the checks as much as possible. Move the check to a separate helper,
__is_bad_mt_xwr(), which allows the guest_rsvd_check usage in
paging_tmpl.h to omit the check entirely for paging32/64 (bad_mt_xwr is
always zero for non-nEPT) while retaining the bitwise-OR of the current
code for the shadow_zero_check in walk_shadow_page_get_mmio_spte().
Add a comment for the bitwise-OR usage in the mmio spte walk to avoid
future attempts to "fix" the code, which is what prompted this
optimization in the first place[*].
Opportunistically remove the superfluous '!= 0' and parantheses, and
use BIT_ULL() instead of open coding its equivalent.
The net effect is that code generation is largely unchanged for
walk_shadow_page_get_mmio_spte(), marginally better for
ept_prefetch_invalid_gpte(), and significantly improved for
paging32/64_prefetch_invalid_gpte().
Note, walk_shadow_page_get_mmio_spte() can't use a templated version of
the memtype/XRW as it works on the host's shadow PTEs, e.g. checks that
KVM hasn't borked its EPT tables. Even if it could be templated, the
benefits of having a single implementation far outweight the few uops
that would be saved for NPT or non-TDP paging, e.g. most compilers
inline it all the way to up kvm_mmu_page_fault().
[*] https://lkml.kernel.org/r/20200108001859.25254-1-sean.j.christopherson@intel.com
Cc: Jim Mattson <jmattson@google.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The KVM MMIO support uses bit 51 as the reserved bit to cause nested page
faults when a guest performs MMIO. The AMD memory encryption support uses
a CPUID function to define the encryption bit position. Given this, it is
possible that these bits can conflict.
Use svm_hardware_setup() to override the MMIO mask if memory encryption
support is enabled. Various checks are performed to ensure that the mask
is properly defined and rsvd_bits() is used to generate the new mask (as
was done prior to the change that necessitated this patch).
Fixes: 28a1f3ac1d ("kvm: x86: Set highest physical address bits in non-present/reserved SPTEs")
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The function nested_vmx_prepare_msr_bitmap() declaration is below its
implementation. So this is meaningless and should be removed.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rename bit() to __feature_bit() to give it a more descriptive name, and
add a macro, feature_bit(), to stuff the X68_FEATURE_ prefix to keep
line lengths manageable for code that hardcodes the bit to be retrieved.
No functional change intended.
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
