KVM: Drop "const" attribute from old memslot in commit_memory_region()
Drop the "const" attribute from @old in kvm_arch_commit_memory_region()
to allow arch specific code to free arch specific resources in the old
memslot without having to cast away the attribute. Freeing resources in
kvm_arch_commit_memory_region() paves the way for simplifying
kvm_free_memslot() by eliminating the last usage of its @dont param.
Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: Refactor error handling for setting memory region
Replace a big pile o' gotos with returns to make it more obvious what
error code is being returned, and to prepare for refactoring the
functional, i.e. post-checks, portion of __kvm_set_memory_region().
Explicitly free an allocated-but-unused dirty bitmap instead of relying
on kvm_free_memslot() if an error occurs in __kvm_set_memory_region().
There is no longer a need to abuse kvm_free_memslot() to free arch
specific resources as arch specific code is now called only after the
common flow is guaranteed to succeed. Arch code can still fail, but
it's responsible for its own cleanup in that case.
Eliminating the error path's abuse of kvm_free_memslot() paves the way
for simplifying kvm_free_memslot(), i.e. dropping its @dont param.
Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove kvm_arch_create_memslot() now that all arch implementations are
effectively nops. Removing kvm_arch_create_memslot() eliminates the
possibility for arch specific code to allocate memory prior to setting
a memslot, which sets the stage for simplifying kvm_free_memslot().
Cc: Janosch Frank <frankja@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: Allocate memslot resources during prepare_memory_region()
Allocate the various metadata structures associated with a new memslot
during kvm_arch_prepare_memory_region(), which paves the way for
removing kvm_arch_create_memslot() altogether. Moving x86's memory
allocation only changes the order of kernel memory allocations between
x86 and common KVM code.
Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: PPC: Move memslot memory allocation into prepare_memory_region()
Allocate the rmap array during kvm_arch_prepare_memory_region() to pave
the way for removing kvm_arch_create_memslot() altogether. Moving PPC's
memory allocation only changes the order of kernel memory allocations
between PPC and common KVM code.
No functional change intended.
Acked-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: Don't free new memslot if allocation of said memslot fails
The two implementations of kvm_arch_create_memslot() in x86 and PPC are
both good citizens and free up all local resources if creation fails.
Return immediately (via a superfluous goto) instead of calling
kvm_free_memslot().
Note, the call to kvm_free_memslot() is effectively an expensive nop in
this case as there are no resources to be freed.
No functional change intended.
Acked-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: Reinstall old memslots if arch preparation fails
Reinstall the old memslots if preparing the new memory region fails
after invalidating a to-be-{re}moved memslot.
Remove the superfluous 'old_memslots' variable so that it's somewhat
clear that the error handling path needs to free the unused memslots,
not simply the 'old' memslots.
Fixes: bc6678a33d9b9 ("KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU update") Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: Allocate new rmap and large page tracking when moving memslot
Reallocate a rmap array and recalcuate large page compatibility when
moving an existing memslot to correctly handle the alignment properties
of the new memslot. The number of rmap entries required at each level
is dependent on the alignment of the memslot's base gfn with respect to
that level, e.g. moving a large-page aligned memslot so that it becomes
unaligned will increase the number of rmap entries needed at the now
unaligned level.
Not updating the rmap array is the most obvious bug, as KVM accesses
garbage data beyond the end of the rmap. KVM interprets the bad data as
pointers, leading to non-canonical #GPs, unexpected #PFs, etc...
The disallow_lpage tracking is more subtle. Failure to update results
in KVM creating large pages when it shouldn't, either due to stale data
or again due to indexing beyond the end of the metadata arrays, which
can lead to memory corruption and/or leaking data to guest/userspace.
Note, the arrays for the old memslot are freed by the unconditional call
to kvm_free_memslot() in __kvm_set_memory_region().
Fixes: 05da45583de9b ("KVM: MMU: large page support") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: Move gpa_val and gpa_available into the emulator context
Move the GPA tracking into the emulator context now that the context is
guaranteed to be initialized via __init_emulate_ctxt() prior to
dereferencing gpa_{available,val}, i.e. now that seeing a stale
gpa_available will also trigger a WARN due to an invalid context.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: Add EMULTYPE_PF when emulation is triggered by a page fault
Add a new emulation type flag to explicitly mark emulation related to a
page fault. Move the propation of the GPA into the emulator from the
page fault handler into x86_emulate_instruction, using EMULTYPE_PF as an
indicator that cr2 is valid. Similarly, don't propagate cr2 into the
exception.address when it's *not* valid.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrew Jones [Fri, 14 Feb 2020 14:59:17 +0000 (15:59 +0100)]
KVM: selftests: Convert some printf's to pr_info's
We leave some printf's because they inform the user the test is being
skipped. QUIET should not disable those. We also leave the printf's
used for help text.
Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrew Jones [Fri, 14 Feb 2020 14:59:16 +0000 (15:59 +0100)]
KVM: selftests: Rework debug message printing
There were a few problems with the way we output "debug" messages.
The first is that we used DEBUG() which is defined when NDEBUG is
not defined, but NDEBUG will never be defined for kselftests
because it relies too much on assert(). The next is that most
of the DEBUG() messages were actually "info" messages, which
users may want to turn off if they just want a silent test that
either completes or asserts. Finally, a debug message output from
a library function, and thus for all tests, was annoying when its
information wasn't interesting for a test.
Rework these messages so debug messages only output when DEBUG
is defined and info messages output unless QUIET is defined.
Also name the functions pr_debug and pr_info and make sure that
when they're disabled we eat all the inputs. The later avoids
unused variable warnings when the variables were only defined
for the purpose of printing.
Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Thu, 23 Jan 2020 18:04:34 +0000 (10:04 -0800)]
KVM: selftests: Time guest demand paging
In order to quantify demand paging performance, time guest execution
during demand paging.
Signed-off-by: Ben Gardon <bgardon@google.com>
[Move timespec-diff to test_util.h] Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Thu, 23 Jan 2020 18:04:33 +0000 (10:04 -0800)]
KVM: selftests: Support multiple vCPUs in demand paging test
Most VMs have multiple vCPUs, the concurrent execution of which has a
substantial impact on demand paging performance. Add an option to create
multiple vCPUs to each access disjoint regions of memory.
Signed-off-by: Ben Gardon <bgardon@google.com>
[guest_code() can't return, use GUEST_ASSERT(). Ensure the number
of guests pages is compatible with the host.] Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Thu, 23 Jan 2020 18:04:32 +0000 (10:04 -0800)]
KVM: selftests: Add support for vcpu_args_set to aarch64 and s390x
Currently vcpu_args_set is only implemented for x86. This makes writing
tests with multiple vCPUs difficult as each guest vCPU must either a.)
do the same thing or b.) derive some kind of unique token from it's
registers or the architecture. To simplify the process of writing tests
with multiple vCPUs for s390 and aarch64, add set args functions for
those architectures.
Signed-off-by: Ben Gardon <bgardon@google.com>
[Fixed array index (num => i) and made some style changes.] Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Thu, 23 Jan 2020 18:04:31 +0000 (10:04 -0800)]
KVM: selftests: Pass args to vCPU in global vCPU args struct
In preparation for supporting multiple vCPUs in the demand paging test,
pass arguments to the vCPU in a consolidated global struct instead of
syncing multiple globals.
Signed-off-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Thu, 23 Jan 2020 18:04:30 +0000 (10:04 -0800)]
KVM: selftests: Add memory size parameter to the demand paging test
Add an argument to allow the demand paging test to work on larger and
smaller guest sizes.
Signed-off-by: Ben Gardon <bgardon@google.com>
[Rewrote parse_size() to simplify and provide user more flexibility as
to how sizes are input. Also fixed size overflow assert.] Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When running the demand paging test with the -u option, the User Fault
FD handler essentially adds an arbitrary delay to page fault resolution.
To enable better simulation of a real demand paging scenario, add a
configurable delay to the UFFD handler.
Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Thu, 20 Feb 2020 17:09:12 +0000 (18:09 +0100)]
KVM: selftests: Add demand paging content to the demand paging test
The demand paging test is currently a simple page access test which, while
potentially useful, doesn't add much versus the existing dirty logging
test. To improve the demand paging test, add a basic userfaultfd demand
paging implementation.
Signed-off-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ben Gardon [Thu, 23 Jan 2020 18:04:27 +0000 (10:04 -0800)]
KVM: selftests: Create a demand paging test
While userfaultfd, KVM's demand paging implementation, is not specific
to KVM, having a benchmark for its performance will be useful for
guiding performance improvements to KVM. As a first step towards creating
a userfaultfd demand paging test, create a simple memory access test,
based on dirty_log_test.
Reviewed-by: Oliver Upton <oupton@google.com> Signed-off-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Guests and hosts don't have to have the same page size. This means
calculations are necessary when selecting the number of guest pages
to allocate in order to ensure the number is compatible with the
host. Provide utilities to help with those calculations and apply
them where appropriate.
We also revert commit bffed38d4fb5 ("kvm: selftests: aarch64:
dirty_log_test: fix unaligned memslot size") and then use
vm_adjust_num_guest_pages() there instead.
Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Consult the 'unconditional IO exiting' and 'use IO bitmaps' VM-execution
controls when checking instruction interception. If the 'use IO bitmaps'
VM-execution control is 1, check the instruction access against the IO
bitmaps to determine if the instruction causes a VM-exit.
Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Tue, 4 Feb 2020 23:26:29 +0000 (15:26 -0800)]
KVM: nVMX: Don't emulate instructions in guest mode
vmx_check_intercept is not yet fully implemented. To avoid emulating
instructions disallowed by the L1 hypervisor, refuse to emulate
instructions by default.
Cc: stable@vger.kernel.org
[Made commit, added commit msg - Oliver] Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Oliver Upton [Fri, 7 Feb 2020 10:36:07 +0000 (02:36 -0800)]
KVM: nVMX: Emulate MTF when performing instruction emulation
Since commit 5f3d45e7f282 ("kvm/x86: add support for
MONITOR_TRAP_FLAG"), KVM has allowed an L1 guest to use the monitor trap
flag processor-based execution control for its L2 guest. KVM simply
forwards any MTF VM-exits to the L1 guest, which works for normal
instruction execution.
However, when KVM needs to emulate an instruction on the behalf of an L2
guest, the monitor trap flag is not emulated. Add the necessary logic to
kvm_skip_emulated_instruction() to synthesize an MTF VM-exit to L1 upon
instruction emulation for L2.
Fixes: 5f3d45e7f282 ("kvm/x86: add support for MONITOR_TRAP_FLAG") Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Li RongQing [Sun, 23 Feb 2020 08:13:12 +0000 (16:13 +0800)]
KVM: fix error handling in svm_hardware_setup
rename svm_hardware_unsetup as svm_hardware_teardown, move
it before svm_hardware_setup, and call it to free all memory
if fail to setup in svm_hardware_setup, otherwise memory will
be leaked
remove __exit attribute for it since it is called in __init
function
Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Miaohe Lin [Sat, 4 Jan 2020 08:56:49 +0000 (16:56 +0800)]
KVM: SVM: Fix potential memory leak in svm_cpu_init()
When kmalloc memory for sd->sev_vmcbs failed, we forget to free the page
held by sd->save_area. Also get rid of the var r as '-ENOMEM' is actually
the only possible outcome here.
Reviewed-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Miaohe Lin [Fri, 21 Feb 2020 14:04:46 +0000 (22:04 +0800)]
KVM: apic: avoid calculating pending eoi from an uninitialized val
When pv_eoi_get_user() fails, 'val' may remain uninitialized and the return
value of pv_eoi_get_pending() becomes random. Fix the issue by initializing
the variable.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Thu, 20 Feb 2020 17:22:04 +0000 (18:22 +0100)]
KVM: nVMX: clear PIN_BASED_POSTED_INTR from nested pinbased_ctls only when apicv is globally disabled
When apicv is disabled on a vCPU (e.g. by enabling KVM_CAP_HYPERV_SYNIC*),
nothing happens to VMX MSRs on the already existing vCPUs, however, all new
ones are created with PIN_BASED_POSTED_INTR filtered out. This is very
confusing and results in the following picture inside the guest:
This is observed with QEMU and 4-vCPU guest: QEMU creates vCPU0, does
KVM_CAP_HYPERV_SYNIC2 and then creates the remaining three.
L1 hypervisor may only check CPU0's controls to find out what features
are available and it will be very confused later. Switch to setting
PIN_BASED_POSTED_INTR control based on global 'enable_apicv' setting.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vitaly Kuznetsov [Thu, 20 Feb 2020 17:22:05 +0000 (18:22 +0100)]
KVM: nVMX: handle nested posted interrupts when apicv is disabled for L1
Even when APICv is disabled for L1 it can (and, actually, is) still
available for L2, this means we need to always call
vmx_deliver_nested_posted_interrupt() when attempting an interrupt
delivery.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Investigation shows that this is due to the uninitialized usage of
struct vapu_svm.ir_list in the svm_set_pi_irte_mode(), which is
called from svm_refresh_apicv_exec_ctrl().
The ir_list is initialized only if AVIC is enabled. So, fixes by
adding a check if AVIC is enabled in the svm_refresh_apicv_exec_ctrl().
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206579 Fixes: 8937d762396d ("kvm: x86: svm: Add support to (de)activate posted interrupts.") Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Tested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Xiaoyao Li [Sun, 16 Feb 2020 10:48:57 +0000 (18:48 +0800)]
KVM: VMX: Add VMX_FEATURE_USR_WAIT_PAUSE
Commit 159348784ff0 ("x86/vmx: Introduce VMX_FEATURES_*") missed
bit 26 (enable user wait and pause) of Secondary Processor-based
VM-Execution Controls.
Add VMX_FEATURE_USR_WAIT_PAUSE flag so that it shows up in /proc/cpuinfo,
and use it to define SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE to make them
uniform.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
wanpeng li [Mon, 17 Feb 2020 10:37:43 +0000 (18:37 +0800)]
KVM: nVMX: Hold KVM's srcu lock when syncing vmcs12->shadow
For the duration of mapping eVMCS, it derefences ->memslots without holding
->srcu or ->slots_lock when accessing hv assist page. This patch fixes it by
moving nested_sync_vmcs12_to_shadow to prepare_guest_switch, where the SRCU
is already taken.
It can be reproduced by running kvm's evmcs_test selftest.
=============================
warning: suspicious rcu usage
5.6.0-rc1+ #53 tainted: g w ioe
-----------------------------
./include/linux/kvm_host.h:623 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by evmcs_test/8507:
#0: ffff9ddd156d00d0 (&vcpu->mutex){+.+.}, at:
kvm_vcpu_ioctl+0x85/0x680 [kvm]
Miaohe Lin [Fri, 14 Feb 2020 02:32:38 +0000 (10:32 +0800)]
KVM: x86: don't notify userspace IOAPIC on edge-triggered interrupt EOI
Commit 13db77347db1 ("KVM: x86: don't notify userspace IOAPIC on edge
EOI") said, edge-triggered interrupts don't set a bit in TMR, which means
that IOAPIC isn't notified on EOI. And var level indicates level-triggered
interrupt.
But commit 3159d36ad799 ("KVM: x86: use generic function for MSI parsing")
replace var level with irq.level by mistake. Fix it by changing irq.level
to irq.trig_mode.
Cc: stable@vger.kernel.org Fixes: 3159d36ad799 ("KVM: x86: use generic function for MSI parsing") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Qian Cai [Mon, 17 Feb 2020 16:48:26 +0000 (11:48 -0500)]
kvm/emulate: fix a -Werror=cast-function-type
arch/x86/kvm/emulate.c: In function 'x86_emulate_insn':
arch/x86/kvm/emulate.c:5686:22: error: cast between incompatible
function types from 'int (*)(struct x86_emulate_ctxt *)' to 'void
(*)(struct fastop *)' [-Werror=cast-function-type]
rc = fastop(ctxt, (fastop_t)ctxt->execute);
Fix it by using an unnamed union of a (*execute) function pointer and a
(*fastop) function pointer.
Fixes: 3009afc6e39e ("KVM: x86: Use a typedef for fastop functions") Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Use document title and chapter markups;
- Add markups for literal blocks;
- Add markups for tables;
- use :field: for field descriptions;
- Add blank lines and adjust indentation.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Use document title and chapter markups;
- Add markups for literal blocks;
- use :field: for field descriptions;
- Add blank lines and adjust indentation.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Use document title and chapter markups;
- Convert tables;
- Add markups for literal blocks;
- use :field: for field descriptions;
- Add blank lines and adjust indentation
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
convert api.txt document to ReST format while trying to keep
its format as close as possible with the authors intent, and
avoid adding uneeded markups.
- Use document title and chapter markups;
- Convert tables;
- Add markups for literal blocks;
- use :field: for field descriptions;
- Add blank lines and adjust indentation
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Use title markups;
- adjust indentation and add blank lines as needed;
- adjust tables to match ReST accepted formats;
- use :field: markups;
- mark code blocks as such.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
docs: kvm: devices/arm-vgic-its.txt to ReST format
- Fix document title to match ReST format
- Convert the table to be properly recognized
- use proper markups for literal blocks
- Some indentation fixes to match ReST
While here, add an index for kvm devices.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Despite being an old document, it contains lots of information
that could still be useful.
The document has a nice style with makes easy to convert to
ReST. So, let's convert it to ReST.
This patch does:
- Use proper markups for titles;
- Mark and proper indent literal blocks;
- don't use an 'o' character for lists;
- other minor changes required for the doc to be parsed.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 12 Feb 2020 12:27:10 +0000 (13:27 +0100)]
KVM: x86: fix WARN_ON check of an unsigned less than zero
The check cpu->hv_clock.system_time < 0 is redundant since system_time
is a u64 and hence can never be less than zero. But what was actually
meant is to check that the result is positive, since kernel_ns and
v->kvm->arch.kvmclock_offset are both s64.
Reported-by: Colin King <colin.king@canonical.com> Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Addresses-Coverity: ("Macro compares unsigned to 0") Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86/mmu: Fix struct guest_walker arrays for 5-level paging
Define PT_MAX_FULL_LEVELS as PT64_ROOT_MAX_LEVEL, i.e. 5, to fix shadow
paging for 5-level guest page tables. PT_MAX_FULL_LEVELS is used to
size the arrays that track guest pages table information, i.e. using a
"max levels" of 4 causes KVM to access garbage beyond the end of an
array when querying state for level 5 entries. E.g. FNAME(gpte_changed)
will read garbage and most likely return %true for a level 5 entry,
soft-hanging the guest because FNAME(fetch) will restart the guest
instead of creating SPTEs because it thinks the guest PTE has changed.
Note, KVM doesn't yet support 5-level nested EPT, so PT_MAX_FULL_LEVELS
gets to stay "4" for the PTTYPE_EPT case.
KVM: nVMX: Use correct root level for nested EPT shadow page tables
Hardcode the EPT page-walk level for L2 to be 4 levels, as KVM's MMU
currently also hardcodes the page walk level for nested EPT to be 4
levels. The L2 guest is all but guaranteed to soft hang on its first
instruction when L1 is using EPT, as KVM will construct 4-level page
tables and then tell hardware to use 5-level page tables.
Miaohe Lin [Fri, 7 Feb 2020 15:22:45 +0000 (23:22 +0800)]
KVM: nVMX: Fix some comment typos and coding style
Fix some typos in the comments. Also fix coding style.
[Sean Christopherson rewrites the comment of write_fault_to_shadow_pgtable
field in struct kvm_vcpu_arch.]
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86/mmu: Avoid retpoline on ->page_fault() with TDP
Wrap calls to ->page_fault() with a small shim to directly invoke the
TDP fault handler when the kernel is using retpolines and TDP is being
used. Single out the TDP fault handler and annotate the TDP path as
likely to coerce the compiler into preferring it over the indirect
function call.
Rename tdp_page_fault() to kvm_tdp_page_fault(), as it's exposed outside
of mmu.c to allow inlining the shim.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Eric Auger [Thu, 6 Feb 2020 10:47:08 +0000 (11:47 +0100)]
selftests: KVM: Replace get_{gdt,idt}_base() by get_{gdt,idt}()
get_gdt_base() and get_idt_base() only return the base address
of the descriptor tables. Soon we will need to get the size as well.
Change the prototype of those functions so that they return
the whole desc_ptr struct instead of the address field.
Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Wei Huang <wei.huang2@amd.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Oliver Upton [Fri, 7 Feb 2020 10:36:06 +0000 (02:36 -0800)]
KVM: x86: Deliver exception payload on KVM_GET_VCPU_EVENTS
KVM allows the deferral of exception payloads when a vCPU is in guest
mode to allow the L1 hypervisor to intercept certain events (#PF, #DB)
before register state has been modified. However, this behavior is
incompatible with the KVM_{GET,SET}_VCPU_EVENTS ABI, as userspace
expects register state to have been immediately modified. Userspace may
opt-in for the payload deferral behavior with the
KVM_CAP_EXCEPTION_PAYLOAD per-VM capability. As such,
kvm_multiple_exception() will immediately manipulate guest registers if
the capability hasn't been requested.
Since the deferral is only necessary if a userspace ioctl were to be
serviced at the same as a payload bearing exception is recognized, this
behavior can be relaxed. Instead, opportunistically defer the payload
from kvm_multiple_exception() and deliver the payload before completing
a KVM_GET_VCPU_EVENTS ioctl.
Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Oliver Upton [Fri, 7 Feb 2020 10:36:05 +0000 (02:36 -0800)]
KVM: nVMX: Handle pending #DB when injecting INIT VM-exit
SDM 27.3.4 states that the 'pending debug exceptions' VMCS field will
be populated if a VM-exit caused by an INIT signal takes priority over a
debug-trap. Emulate this behavior when synthesizing an INIT signal
VM-exit into L1.
Fixes: 4b9852f4f389 ("KVM: x86: Fix INIT signal handling in various CPU states") Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Oliver Upton [Fri, 7 Feb 2020 10:36:04 +0000 (02:36 -0800)]
KVM: x86: Mask off reserved bit from #DB exception payload
KVM defines the #DB payload as compatible with the 'pending debug
exceptions' field under VMX, not DR6. Mask off bit 12 when applying the
payload to DR6, as it is reserved on DR6 but not the 'pending debug
exceptions' field.
Fixes: f10c729ff965 ("kvm: vmx: Defer setting of DR6 until #DB delivery") Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Marc Zyngier [Fri, 7 Feb 2020 16:34:10 +0000 (16:34 +0000)]
KVM: Disable preemption in kvm_get_running_vcpu()
Accessing a per-cpu variable only makes sense when preemption is
disabled (and the kernel does check this when the right debug options
are switched on).
For kvm_get_running_vcpu(), it is fine to return the value after
re-enabling preemption, as the preempt notifiers will make sure that
this is kept consistent across task migration (the comment above the
function hints at it, but lacks the crucial preemption management).
While we're at it, move the comment from the ARM code, which explains
why the whole thing works.
Fixes: 7495e22bb165 ("KVM: Move running VCPU from ARM to common code"). Cc: Paolo Bonzini <pbonzini@redhat.com> Reported-by: Zenghui Yu <yuzenghui@huawei.com> Tested-by: Zenghui Yu <yuzenghui@huawei.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/318984f6-bc36-33a3-abc6-bf2295974b06@huawei.com
Message-id: <20200207163410.31276-1-maz@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Tue, 11 Feb 2020 17:40:58 +0000 (18:40 +0100)]
KVM: x86: do not reset microcode version on INIT or RESET
Do not initialize the microcode version at RESET or INIT, only on vCPU
creation. Microcode updates are not lost during INIT, and exact
behavior across a warm RESET is not specified by the architecture.
Since we do not support a microcode update directly from the hypervisor,
but only as a result of userspace setting the microcode version MSR,
it's simpler for userspace if we do nothing in KVM and let userspace
emulate behavior for RESET as it sees fit.
Userspace can tie the fix to the availability of MSR_IA32_UCODE_REV in
the list of emulated MSRs.
Reported-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linus Torvalds [Mon, 10 Feb 2020 00:05:50 +0000 (16:05 -0800)]
Merge tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull more Kbuild updates from Masahiro Yamada:
- fix randconfig to generate a sane .config
- rename hostprogs-y / always to hostprogs / always-y, which are more
natual syntax.
- optimize scripts/kallsyms
- fix yes2modconfig and mod2yesconfig
- make multiple directory targets ('make foo/ bar/') work
* tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: make multiple directory targets work
kconfig: Invalidate all symbols after changing to y or m.
kallsyms: fix type of kallsyms_token_table[]
scripts/kallsyms: change table to store (strcut sym_entry *)
scripts/kallsyms: rename local variables in read_symbol()
kbuild: rename hostprogs-y/always to hostprogs/always-y
kbuild: fix the document to use extra-y for vmlinux.lds
kconfig: fix broken dependency in randconfig-generated .config
Linus Torvalds [Sun, 9 Feb 2020 23:51:46 +0000 (15:51 -0800)]
Merge tag 'zonefs-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs
Pull new zonefs file system from Damien Le Moal:
"Zonefs is a very simple file system exposing each zone of a zoned
block device as a file.
Unlike a regular file system with native zoned block device support
(e.g. f2fs or the on-going btrfs effort), zonefs does not hide the
sequential write constraint of zoned block devices to the user. As a
result, zonefs is not a POSIX compliant file system. Its goal is to
simplify the implementation of zoned block devices support in
applications by replacing raw block device file accesses with a richer
file based API, avoiding relying on direct block device file ioctls
which may be more obscure to developers.
One example of this approach is the implementation of LSM
(log-structured merge) tree structures (such as used in RocksDB and
LevelDB) on zoned block devices by allowing SSTables to be stored in a
zone file similarly to a regular file system rather than as a range of
sectors of a zoned device. The introduction of the higher level
construct "one file is one zone" can help reducing the amount of
changes needed in the application while at the same time allowing the
use of zoned block devices with various programming languages other
than C.
Zonefs IO management implementation uses the new iomap generic code.
Zonefs has been successfully tested using a functional test suite
(available with zonefs userland format tool on github) and a prototype
implementation of LevelDB on top of zonefs"
* tag 'zonefs-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
zonefs: Add documentation
fs: New zonefs file system
projects / mirror_ubuntu-jammy-kernel.git / log