Bus lock debug exception is a feature that can notify the kernel by
generate an #DB trap after the instruction acquires a bus lock when
CPL>0. This allows the kernel to enforce user application throttling or
mitigations.
This feature is enumerated via CPUID.(EAX=7,ECX=0).ECX[bit 24].
Backports 06e878b413766778a53be3d25c0373a23679d039
We were fudging TBI1 enabled to speed up the generated code.
Now that we've improved the code generation, remove this.
Also, tidy the comment to reflect the current code.
The pauth test was testing a kernel address (-1) and making
incorrect assumptions about TBI1; stick to userland addresses.
Backports 16c849784873d10d0da257d698e391fddea1f0e4
The float-access functions stfl_*, stfq*, ldfl* and ldfq* are now
unused; remove them. (Accesses to float64 and float32 types can be
made with the ldl/stl/ldq/stq functions, as float64 and float32 are
guaranteed to be typedefs for normal integer types.)
Backports f930224fffead81e23e699517d1351e33890b6f7
When working with performance monitoring counters, we look at
MDCR_EL2.HPMN as part of the check whether a counter is enabled. This
check fails, because MDCR_EL2.HPMN is reset to 0, meaning that no
counters are "enabled" for < EL2.
That's in violation of the Arm specification, which states that
> On a Warm reset, this field [MDCR_EL2.HPMN] resets to the value in
> PMCR_EL0.N
That's also what a comment in the code acknowledges, but the necessary
adjustment seems to have been forgotten when support for more counters
was added.
This change fixes the issue by setting the reset value to PMCR.N, which
is four.
Backports d3c1183ffeb71ca3a783eae3d7e1c51e71e8a621
In cpu_exec() we have a longstanding workaround for compilers which
do not correctly implement the part of the sigsetjmp()/siglongjmp()
spec which requires that local variables which are not changed
between the setjmp and the longjmp retain their value.
I recently ran across the upstream clang bug report for this; add a
link to it to the comment describing the workaround, and generally
expand the comment, so that we have a reasonable chance in future of
understanding why it's there and determining when we can remove it,
assuming clang eventually fixes the bug.
Remove the /* buggy compiler */ comments on the #else and #endif:
they don't add anything to understanding and are somewhat misleading
since they're sandwiching the code path for *non*-buggy compilers.
Backports e6a41a045c298538d303cd8fe8d7ae29a0c066ad
cpsr has been treated as being the same as spsr, but it isn't.
Since PSTATE_SS isn't in cpsr, remove it and move it into env->pstate.
This allows us to add support for CPSR_DIT, adding helper functions
to merge SPSR_ELx to and from CPSR.
Backports f944a854ce4007000accf7c191b5b52916947198
Add support for FEAT_DIT. DIT (Data Independent Timing) is a required
feature for ARMv8.4. Since virtual machine execution is largely
nondeterministic and TCG is outside of the security domain, it's
implemented as a NOP.
Backports dc8b18534ea1dcc90d80ad9a61a3b0aa7eb312fb
The FW and AW bits of SCR_EL3 are RES1 only in some contexts. Force them
to 1 only when there is no support for AArch32 at EL1 or above.
The reset value will be 0x30 only if the CPU is AArch64-only; if there
is support for AArch32 at EL1 or above, it will be reset to 0.
Also adds helper function isar_feature_aa64_aa32_el1 to check if AArch32
is supported at EL1 or above.
Backports 10d0ef3e6cfe228df4b2d3e27325f1b0e2b71fd5
Expose the VMX exit/entry load pkrs control bits in
VMX_TRUE_EXIT_CTLS/VMX_TRUE_ENTRY_CTLS MSRs to guest, which supports the
PKS in nested VM.
Backports 52a44ad2b92ba4cd81c2b271cd5e4a2d820e91fc
Protection Keys for Supervisor-mode pages is a simple extension of
the PKU feature that QEMU already implements. For supervisor-mode
pages, protection key restrictions come from a new MSR. The MSR
has no XSAVE state associated to it.
PKS is only respected in long mode. However, in principle it is
possible to set the MSR even outside long mode, and in fact
even the XSAVE state for PKRU could be set outside long mode
using XRSTOR. So do not limit the migration subsections for
PKRU and PKRS to long mode.
Backports e7e7bdababeefff10736c6adf410c66d2f0d46fe
This patch fixes a translation bug for a subset of x86 BMI instructions
such as the following:
c4 e2 f9 f7 c0 shlxq %rax, %rax, %rax
Currently, these incorrectly generate an undefined instruction exception
when SSE is disabled via CR4, while instructions like "shrxq" work fine.
The problem appears to be related to BMI instructions encoded using VEX
and with a mandatory prefix of "0x66" (data). Instructions with this
data prefix (such as shlxq) are currently rejected. Instructions with
other mandatory prefixes (such as shrxq) translate as expected.
This patch removes the incorrect check in "gen_sse" that causes the
exception to be generated. For the non-BMI cases, the check is
redundant: prefixes are already checked at line 3696.
Buglink: https://bugs.launchpad.net/qemu/+bug/1748296
Backports 51909241d26fe6fe18a08def93ccc8273f61a8b3
32-bit targets by definition do not support long mode; therefore, the
bit must be masked in the features supported by the accelerator.
As a side effect, this avoids setting up the 0x80000008 CPUID leaf
for
qemu-system-i386 -cpu host
which since commit 5a140b255d ("x86/cpu: Use max host physical address
if -cpu max option is applied") would have printed this error:
qemu-system-i386: phys-bits should be between 32 and 36 (but is 48)
Backports 5ea9e9e239db83391a39c09f1de63c4099c20df5
commit 568496c0c0f1 ("cpu: Add callback to check architectural") and
commit 3826121d9298 ("target-arm: Implement checking of fired")
introduced an ARM-specific hack for cpu_check_watchpoint.
Make debug_check_watchpoint optional, and move it to tcg_ops.
Backports c73bdb35a91fb6b17c2c93b1ba381fc88a406f8d
commit 40612000599e ("arm: Correctly handle watchpoints for BE32 CPUs")
introduced this ARM-specific, TCG-specific hack to adjust the address,
before checking it with cpu_check_watchpoint.
Make adjust_watchpoint_address optional and move it to tcg_ops.
Backports 9ea9087bb4a86893e4ac6ff643837937dc9e5849
The TCG-specific CPU methods will be moved to a separate struct,
to make it easier to move accel-specific code outside generic CPU
code in the future. Start by moving tcg_initialize().
The new CPUClass.tcg_opts field may eventually become a pointer,
but keep it an embedded struct for now, to make code conversion
easier.
Backports e9e51b7154404efc9af8735ab87c658a9c434cfd
cc->do_interrupt is in theory a TCG callback used in accel/tcg only,
to prepare the emulated architecture to take an interrupt as defined
in the hardware specifications,
but in reality the _do_interrupt style of functions in targets are
also occasionally reused by KVM to prepare the architecture state in a
similar way where userspace code has identified that it needs to
deliver an exception to the guest.
In the case of ARM, that includes:
1) the vcpu thread got a SIGBUS indicating a memory error,
and we need to deliver a Synchronous External Abort to the guest to
let it know about the error.
2) the kernel told us about a debug exception (breakpoint, watchpoint)
but it is not for one of QEMU's own gdbstub breakpoints/watchpoints
so it must be a breakpoint the guest itself has set up, therefore
we need to deliver it to the guest.
So in order to reuse code, the same arm_do_interrupt function is used.
This is all fine, but we need to avoid calling it using the callback
registered in CPUClass, since that one is now TCG-only.
Fortunately this is easily solved by replacing calls to
CPUClass::do_interrupt() with explicit calls to arm_do_interrupt().
Backports 853bfef4e6d60244fd131ec55bbf1e7caa52599b. We don't support
KVM, so we just bring the comment addition over.
I really don't want to support all these backends on an ARM-focused
backend.
Also the notion of someone saying
"yes, I would like to compute things using MIPS/SPARC/PPC instead of
literally anything else" is wild to me.
Thus, I will solve the problem by simply not thinking about it
whatsoever.
This exports the constraint sets from tcg_target_op_def to
a place we will be able to manipulate more in future.
Backports 4c22e840880e935ea07f1c4352bd8c54febff4df
This eliminates the target-specific function target_parse_constraint
and folds it into the single caller, process_op_defs. Since this is
done directly into the switch statement, duplicates are compilation
errors rather than silently ignored at runtime.
Backports 358b492392ad91d45a9714f7cd28fc1d83ffd8b
Create symbolic constants for all low-byte-addressable
and second-byte-addressable registers. Create a symbol
for the registers that need reserving for softmmu.
There is no functional change for 's', as this letter is
only used for i386. The BYTEL name is correct for the
action we wish from the constraint.
Backports df903b94b3c6fa515da7cf2103513ade06ab0d0f
Rather than check the type when filling in the constraint,
check it when matching the constant. This removes the only
use of the type argument to target_parse_constraint.
Backports c7c778b5b9b7865a3e7200805ac561c5d334b8d0
