Backend domain may be independently destroyed - there is no
synchronization of libxl structures (including /libxl tree) elsewhere.
Backend might also remove the device info from its backend xenstore
subtree on its own.
We have various cases (not comprehensive list):
- both frontend and backend operational: after setting
be/state=XenbusStateClosing backend wait for frontend confirmation
and respond with be/state=XenbusStateClosed; then libxl in dom0
remove frontend entries and libxl in backend domain (which may be the
same) remove backend entries
- unresponsive backend/frontend: after a timeout, force=1 is used to remove
frontend entries, instead of just setting
be/state=XenbusStateClosing; then wait for be/state=XenbusStateClosed.
If that timeout too, remove both frontend and backend entries
- backend gone, with this patch: no place for setting/waiting on
be/state - go directly to removing frontend entries, without waiting
for be/state=XenbusStateClosed (this is the difference vs force=1)
Without this patch the end result is similar, both frontend and backend
entries are removed, but in case of backend gone:
- libxl waits for be/state=XenbusStateClosed (and obviously timeout)
- return value from the function signal an error, which for example
confuse libvirt - it thinks the device remove failed, so is still
there
If such situation is detected, do not fail the removal, but finish the
cleanup of the frontend side and return 0.
This is just workaround, the real fix should watch when the device
backend is removed (including backend domain destruction) and remove
frontend at that time. And report such event to higher layer code, so
for example libvirt could synchronize its state.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
While this means quite some reduction of (source) code, the main
purpose is to no longer have exceptions raised from other than stubs.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Add the shim build symbol file and remove the xen-shim binary (which
is no longer created).
Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
I have no idea what *.1 is meant to cover. Instead also exclude
preprocessed and non-source assembly files.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
I have no idea what *.d1 is supposed to refer to - we only have .*.d
and .*.d2 files (note also the leading dot). Also switch to passing
-name instead of -path to find - that's a requirement for .*.d et al to
work, but would probably have been better from the beginning.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Commit 119ee4d773 ("tools/libxc: Tolerate specific zero-content records
in migration v2 streams") meant tolerate those, but failed to set rc
accordingly.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
This is in preparation to make hvm_x2apic_msr_read() take a const vcpu
pointer. One modification is to alter vlapic_get_tmcct() to not use current.
This in turn needs an alteration to hvm_get_guest_time_fixed(), which is safe
because the only mutable action it makes is to take the domain plt lock.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The default case of vmx_msr_write_intercept() in particular is very tangled.
First of all, fold long_mode_do_msr_{read,write}() into their callers. These
functions were split out in the past because of the 32bit build of Xen, but it
is unclear why the cases weren't simply #ifdef'd in place.
Next, invert the vmx_write_guest_msr()/is_last_branch_msr() logic to break if
the condition is satisfied, rather than nesting if it wasn't. This allows the
wrmsr_hypervisor_regs() call to be un-nested with respect to the other default
logic.
No practical difference from a guests point of view.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
In hardware, when PCID support is enabled and the NOFLUSH bit is set
when writing a CR3 value, the hardware will clear that that bit and
change the CR3 without flushing the TLB. hvm_set_cr3(), however, was
ignoring this bit; the result was that post-vm_event checks detected
an invalid CR3 value and crashed the domain.
Handle NOFLUSH in hvm_set_cr3() by:
1. Clearing the bit
2. Passing a "noflush" flag to lower-level cr3 setting functions to
indicate that a flush should not be performed.
Also clear X86_CR3_NOFLUSH when reporting CR3 monitored CR3 writes.
This allows introspection to be used on VMs whose operating system uses
the NOFLUSH bit.
Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reported-by: Bitweasil <bitweasil@cryptohaze.com>
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Basically, instead of converting integers to s_time_t
at usage time (hot paths), do the convertion when the
values are set (cold paths).
This applies to the timeslice and the ratelimit
parameters of Credit1.
Note that, when changing the type of the fields of
struct csched_private (from unsigned to s_time_t),
ncpus is moved up a bit, for better packing.
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
We don't know what is the state of the TLBs when booting Xen. To avoid
stale entries, it is necessary to flush the TLBs before turning on the
MMU.
Reported-by: Iain Hunter <iain@hunterembedded.co.uk>
Signed-off-by: Julien Grall <julien.gralL@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
This patch was originally released as part of XSA-226. It retains the same
command line syntax (as various downstreams are mitigating XSA-226 using this
mechanism) but the defaults have been updated due to the revised XSA-226
patched, after which transitive grants are believed to functioning
properly.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
... for non-existent MSRs: wrmsr_hypervisor_regs()'s comment clearly
says that the function returns 0 for unrecognized MSRs, so
{svm,vmx}_msr_write_intercept() should not convert this into success. We
don't want to unconditionally fail the access though, as we can't be
certain the list of handled MSRs is complete enough for the guest types
we care about, so instead mirror what we do on the read paths and probe
the MSR to decide whether to raise #GP.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
There a bunch of bits in CR4 that should be allowed to be set directly
by the guest without requiring Xen intervention, currently this is
already done by passing through guest writes into the CR4 used when
running in non-root mode, but taking an expensive vmexit in order to
do so.
xenalyze reports the following when running a PV guest in shim mode:
CR_ACCESS 3885950 6.41s 17.04% 3957 cyc { 2361| 3378| 7920}
cr4 3885940 6.41s 17.04% 3957 cyc { 2361| 3378| 7920}
cr3 1 0.00s 0.00% 3480 cyc { 3480| 3480| 3480}
*[ 0] 1 0.00s 0.00% 3480 cyc { 3480| 3480| 3480}
cr0 7 0.00s 0.00% 7112 cyc { 3248| 5960|17480}
clts 2 0.00s 0.00% 4588 cyc { 3456| 5720| 5720}
After this change this turns into:
CR_ACCESS 12 0.00s 0.00% 9972 cyc { 3680|11024|24032}
cr4 2 0.00s 0.00% 17528 cyc {11024|24032|24032}
cr3 1 0.00s 0.00% 3680 cyc { 3680| 3680| 3680}
*[ 0] 1 0.00s 0.00% 3680 cyc { 3680| 3680| 3680}
cr0 7 0.00s 0.00% 9209 cyc { 4184| 7848|17488}
clts 2 0.00s 0.00% 8232 cyc { 5352|11112|11112}
Note that this optimized trapping is currently only applied to guests
running with HAP on Intel hardware. If using shadow paging more CR4
bits need to be unconditionally trapped, which makes this approach
unlikely to yield any important performance improvements.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
With everyone having their tags below agreeing that putting things the
other way around in the comparison makes things easier to understand, do
that rearrangement while changing the line anyway.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.apu@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
At this moment the CPUID events for the AMD architecture are not
forwarded to the monitor layer.
This patch adds the CPUID event to the common capabilities and then
forwards the event to the monitor layer.
Signed-off-by: Alexandru Isaila <aisaila@bitdefender.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
There are multiple problems, not necesserily limited to:
* Guests which configure event channels via hvmop_set_evtchn_upcall_vector(),
or which hit %cr8 emulation will cause Xen to fall over a NULL vlapic->regs
pointer.
* On Intel hardware, disabling the TPR_SHADOW execution control without
reenabling CR8_{LOAD,STORE} interception means that the guests %cr8
accesses interact with the real TPR. Amongst other things, setting the
real TPR to 0xf blocks even IPIs from interrupting this CPU.
* On hardware which sets up the use of Interrupt Posting, including
IOMMU-Posting, guests run without the appropriate non-root configuration,
which at a minimum will result in dropped interrupts.
Whether no-LAPIC mode is of any use at all remains to be seen.
This is XSA-256.
Reported-by: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
There may still be active mappings, which would trigger the respective
BUG_ON(). Split the loop into one dealing with the page attributes and
the second (when the first fully passed) freeing the pages. Return an
error if any pages still have pending references.
This is part of XSA-255.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
... by writing status GFNs to it. Introduce a second array instead.
Also implement gnttab_status_gmfn() properly now that the information is
suitably being tracked.
While touching it anyway, remove a misguided (but luckily benign) upper
bound check from gnttab_shared_gmfn(): We should never access beyond the
bounds of that array.
This is part of XSA-255.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
It very likely was a mistake (copy-and-paste from domain cleanup code)
to implicitly unpin here: The caller should really unpin itself before
(or after, if they so wish) requesting the page to be removed.
This is XSA-252.
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
common/grant_table.c:cache_flush() grabs the rcu lock for the current
domain, but only releases it on error paths.
Note that this is not a security issue, as the preempt count is used
exclusively for assertions at the moment.
Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Having pv_soft_rdtsc() emulate all parts of an rdtscp is awkward, and gets in
the way of some intended cleanup.
* Drop the rdtscp parameter and always make the caller responsible for ecx
updates when appropriate.
* Switch the function from being void, and return the main timestamp in the
return value.
The regs parameter is still needed, but only for the stats collection, once
again bringing into question their utility. The parameter can however switch
to being const.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
If the CPU pipeline supports RDTSCP or RDPID, a guest can observe the value in
MSR_TSC_AUX, irrespective of whether the relevant CPUID features are
advertised/hidden.
At the moment, paravirt_ctxt_switch_to() only writes to MSR_TSC_AUX if
TSC_MODE_PVRDTSCP mode is enabled, but this is not the default mode.
Therefore, default PV guests can read the value from a previously scheduled
HVM vcpu, or TSC_MODE_PVRDTSCP-enabled PV guest.
Alter the PV path to always write to MSR_TSC_AUX, using 0 in the common case.
To amortise overhead cost, introduce wrmsr_tsc_aux() which performs a lazy
update of the MSR, and use this function consistently across the codebase.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
32-bit domain is able to select the instruction (ARM vs Thumb) to use
when boot a new vCPU via CPU_ON. This is indicated via bit[0] of the
entry point address (see "T32 support" in PSCI v1.1 DEN0022D). bit[0]
must be cleared when setting the PC.
At the moment, Xen is setting the CPSR.T but never clear bit[0]. Clear
it to match the specification.
At the same time, slighlty rework the code to make clear thumb is only for
32-bit domain. Lastly, take the opportunity to switch is_thumb from int
to bool.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
PSCI 1.0 added the error return PSCI_INVALID_ADDRESS. It is used to
indicate the entry point address is known to be invalid.
In Xen case, this error could be returned when a 64-bit vCPU is using a
Thumb entry address.
For PSCI 0.1 implementation, return PSCI_INVALID_PARAMETERS instead.
Suggested-by: mirela.simonovic@aggios.com
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Cc: mirela.simonovic@aggios.com
A bunch of PSCI functions are not prefixed with static despite no one is
using them outside the file and the prototype is not available in
psci.h.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Xen is printing the same way the PSCI version for 0.1, 0.2 and later.
The only different is the former is hardcoded.
Furthermore PSCI is now used for other things than SMP bring up. So only
print the PSCI version in psci_init.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Currently, the behavior of do_common_cpu will slightly change depending
on the PSCI version passed in parameter. Looking at the code, more the
specific 0.2 behavior could move out of the function or adapted for 0.1:
- x0/r0 can be updated on PSCI 0.1 because general purpose registers
are undefined upon CPU on. This was deduced from the spec not
mentioning the state of general purpose registers on CPU on.
- PSCI 0.1 does not defined PSCI_ALREADY_ON. However, it would be
safer to bail out if the CPU is already on.
Based on this, the parameter 'ver' is removed and do_psci_cpu_on
(implementation for PSCI 0.1) is adapted to avoid returning
PSCI_ALREADY_ON.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr.babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Now that we've standardised on SMCCC v1.1 to perform the branch
prediction invalidation, let's drop the previous band-aid. If vendors
haven't updated their firmware to do SMCCC 1.1, they haven't updated
PSCI either, so we don't loose anything.
This is aligned with the Linux commit 3a0a397ff5ff.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
One of the major improvement of SMCCC v1.1 is that it only clobbers the
first 4 registers, both on 32 and 64bit. This means that it becomes very
easy to provide an inline version of the SMC call primitive, and avoid
performing a function call to stash the registers that woudl otherwise
be clobbered by SMCCC v1.0.
This patch has been adapted to Xen from Linux commit f2d3b2e8759a. The
changes mades are:
- Using Xen coding style
- Remove HVC as not used by Xen
- Add arm_smccc_res structure
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
PSCI 1.0 and later allows the SMCCC version to be (indirectly) probed
via PSCI_FEATURES. If the PSCI_FEATURES does not exist (PSCI 0.2 or
earlier) and the function returns an error, then we assume SMCCC 1.0
is implemented.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Add macros SMCCC_VERSION, SMCCC_VERSION_{MINOR, MAJOR} to easily convert
between a 32-bit value and a version number. The encoding is based on
2.2.2 in "Firmware interfaces for mitigation CVE-2017-5715" (ARM DEN 0070A).
Also re-use them to define ARM_SMCCC_VERSION_1_0 and ARM_SMCCC_VERSION_1_1.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
The function SMCCC_ARCH_WORKAROUND_1 will be called by the guest for
hardening the branch predictor. So we want the handling to be as fast as
possible.
As the mitigation is applied on every guest exit, we can check for the
call before saving all the context and return very early.
For now, only provide a fast path for HVC64 call. Because the code rely
on 2 registers, x0 and x1 are saved in advance.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr.babchuk@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
SMCCC 1.1 offers firmware-based CPU workarounds. In particular,
SMCCC_ARCH_WORKAROUND_1 provides BP hardening for variant 2 of XSA-254
(CVE-2017-5715).
If the hypervisor has some mitigation for this issue, report that we
deal with it using SMCCC_ARCH_WORKAROUND_1, as we apply the hypervisor
workaround on every guest exit.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr.babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
The new SMC Calling Convention (v1.1) allows for a reduced overhead when
calling into the firmware, and provides a new feature discovery
mechanism. See "Firmware interfaces for mitigating CVE-2017-5715"
ARM DEN 00070A.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr.babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
At the moment, Xen provides virtual PSCI interface compliant with 0.1
and 0.2. Since them, the specification has been updated and the latest
version is 1.1 (see ARM DEN 0022D).
>From an implementation point of view, only PSCI_FEATURES is mandatory.
The rest is optional and can be left unimplemented for now.
At the same time, the compatible for PSCI node have been updated to
expose "arm,psci-1.0".
Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: mirela.simonovic@aggios.com
Some PSCI functions are only available in the 32-bit version. After
recent changes, Xen always needs to know whether the call was made using
32-bit id or 64-bit id. So we don't emulate reserved one.
With the current naming scheme, it is not easy to know which call
supports 32-bit and 64-bit id. So rework the definitions to encode the
version in the name. From now the functions will be named PSCI_0_2_FNxx
where xx is 32 or 64.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babchuk <volodymyr.babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
c/s d2f86bf604 which introduced "struct hvm_save_descriptor *d" accidentally
ended up shadowing the "struct domain *d" function parameter. Rename the
former to desc.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
If the required features are present.
Modify as-option-add to add an option in case the test fails, and use
it to detect whether the required clang integrated assembler features
are present.
This patch has been tested with clang 3.5, clang 6, gcc 6.4.0 without
retpoline support and gcc 7.3.1 with retpoline support.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
When files are added or removed /dev/null is used as a place
holder name in the patch for the absent file. Don't try and
find a MAINTAINER for this place holder, it only ever flags
and then spams THE REST, behaviour for a real filename is
unchanged.
Signed-off-by: Alan Robinson <Alan.Robinson@ts.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>