hvf_reset_vcpu() duplicates actions performed by x86_cpu_reset(). The
difference is that hvf_reset_vcpu() stores initial values directly to
VMCS while x86_cpu_reset() stores it in CPUX86State and then
cpu_synchronize_all_post_init() or cpu_synchronize_all_post_reset()
flushes CPUX86State into VMCS. That makes hvf_reset_vcpu() a kind of
no-op.
Here's the trace of CPU state modifications during VM start:
hvf_reset_vcpu (resets VMCS)
cpu_synchronize_all_post_init (overwrites VMCS fields written by
hvf_reset_vcpu())
cpu_synchronize_all_states
hvf_reset_vcpu (resets VMCS)
cpu_synchronize_all_post_reset (overwrites VMCS fields written by
hvf_reset_vcpu())
General purpose registers, system registers, segment descriptors, flags
and IP are set by hvf_put_segments() in post-init and post-reset,
therefore it's safe to remove them from hvf_reset_vcpu().
PDPTE initialization can be dropped because Intel SDM (26.3.1.6 Checks
on Guest Page-Directory-Pointer-Table Entries) doesn't require PDPTE to
be clear unless PAE is used: "A VM entry to a guest that does not use
PAE paging does not check the validity of any PDPTEs."
And if PAE is used, PDPTE's are initialized from CR3 in macvm_set_cr0().
Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200630102824.77604-8-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The only useful purpose of hvf_reset_vcpu() is to clear "IA-32e mode
guest" (LMA) VM-Entry control. But it can be moved to macvm_set_cr0()
which is indirectly used by post-init and post-reset to flush emulator
state. That enables clean removal of hvf_reset_vcpu().
LMA is set only if IA32_EFER.LME = 1, according to Intel SDM "9.8.5
Initializing IA-32e Mode" and "9.8.5.4 Switching Out of IA-32e Mode
Operation", otherwise the entry control can be safely cleared.
Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200630102824.77604-7-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Intel SDM "9.8.5 Initializing IA-32e Mode" and "9.8.5.4 Switching Out of
IA-32e Mode Operation" define activation and deactivation of long mode
only upon a change of CR0.PG but current code invokes exit_long_mode()
unconditionally until LME is cleared.
Signed-off-by: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200630102824.77604-6-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
hvf lacks an implementation of cpu_synchronize_pre_loadvm().
Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200630102824.77604-4-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
cpu_synchronize_state() is currently no-op for hvf but BIOS will hang in
vAPIC option ROM when cpu_synchronize_state() is wired to
hvf_cpu_synchronize_state().
cpu_synchronize_state() state is called from vapic_write() during option
ROM initialization. It sets dirty flag on the cpu. macvm_set_rip() is
then invoked to advance IP after the I/O write to vAPIC port.
macvm_set_rip() only modifies VMCS, it doesn't change env->eip.
Therefore on the next iteration of vCPU loop, vcpu_dirty flag is checked
and hvf_put_registers() overwrites correct RIP in VMCS with the value of
env->eip that points to the I/O write instruction. Execution of the CPU
gets stuck on the instruction.
The issue can be avoided if eip doesn't contain stale value when dirty
flag is set on cpu.
Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200630102824.77604-2-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-14-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There's no similar field in CPUX86State, but it's needed for MMIO traps.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-13-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The lazy flags are still needed for instruction decoder.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-12-r.bolshakov@yadro.com>
[Move struct to target/i386/cpu.h - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
HVFX86EmulatorState carries it's own copy of x86 registers. It can be
dropped in favor of regs in generic CPUX86State.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-11-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use the ones provided in target/i386/cpu.h instead.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-10-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
HVFX86EmulatorState carries it's own copy of x86 flags. It can be
dropped in favor of eflags in generic CPUX86State.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-9-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The field is used to print address of instructions that have no parser
in decode_invalid(). RIP from VMCS is saved into fetch_rip before
decoding starts but it's also saved into env->eip in load_regs().
Therefore env->eip can be used instead of fetch_rip.
While at it, correct address printed in decode_invalid(). It prints an
address before the unknown instruction.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-8-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Drop and replace rip field from HVFX86EmulatorState in favor of eip from
common CPUX86State.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-7-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
There's no need to read VMCS twice, instruction length is already
available in ins_len.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-6-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-5-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
They're either declared elsewhere or have no use.
While at it, rename _hvf_cpu_synchronize_post_init() to
do_hvf_cpu_synchronize_post_init().
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-3-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
"sysemu/hvf.h" is intended for inclusion in generic code. However it
also contains several hvf definitions and declarations, including
HVFState that are used only inside "hvf.c". "hvf-i386.h" would be more
appropriate place to define HVFState as it's only included by "hvf.c"
and "x86_task.c".
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200528193758.51454-2-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit acb9f95a removed boundary checks for ID and VCPU ID. After that,
the max definitions of that boundaries are not required anymore. This
commit is only a code cleanup.
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Message-Id: <20200323200538.202164-1-jcfaracco@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The sequence of instructions exposes an issue:
sti
hlt
Interrupts cannot be delivered to hvf after hlt instruction cpu because
HF_INHIBIT_IRQ_MASK is set just before hlt is handled and never reset
after moving instruction pointer beyond hlt.
So, after hvf_vcpu_exec() returns, CPU thread gets locked up forever in
qemu_wait_io_event() (cpu_thread_is_idle() evaluates inhibition
flag and considers the CPU idle if the flag is set).
Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200328174411.51491-1-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The address_space_rw() function allows either reads or writes
depending on the is_write argument passed to it; this is useful
when the direction of the access is determined programmatically
(as for instance when handling the KVM_EXIT_MMIO exit reason).
Under the hood it just calls either address_space_write() or
address_space_read_full().
We also use it a lot with a constant is_write argument, though,
which has two issues:
* when reading "address_space_rw(..., 1)" this is less
immediately clear to the reader as being a write than
"address_space_write(...)"
* calling address_space_rw() bypasses the optimization
in address_space_read() that fast-paths reads of a
fixed length
This commit was produced with the included Coccinelle script
scripts/coccinelle/exec_rw_const.cocci.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20200218112457.22712-1-peter.maydell@linaro.org>
[PMD: Update macvm_set_cr0() reported by Laurent Vivier]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Since its introduction in commit ac1970fbe8, address_space_rw()
takes a boolean 'is_write' argument. Fix the codebase by using
an explicit boolean type.
This commit was produced with the included Coccinelle script
scripts/coccinelle/exec_rw_const.
Inspired-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
This commit was produced with the included Coccinelle script
scripts/coccinelle/exec_rw_const.
Two lines in hw/net/dp8393x.c that Coccinelle produced that
were over 80 characters were re-wrapped by hand.
Suggested-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Add the property and plumb it in TCG and HVF (the latter of which
tried to support returning a constant value but used the wrong MSR).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1579544504-3616-3-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Previous implementation in hvf_inject_interrupts() would always inject
VMCS_INTR_T_SWINTR even when VMCS_INTR_T_HWINTR was required. Now
correctly determine when VMCS_INTR_T_HWINTR is appropriate versus
VMCS_INTR_T_SWINTR.
Make sure to clear ins_len and has_error_code when ins_len isn't
valid and error_code isn't set.
Signed-off-by: Cameron Esfahani <dirty@apple.com>
Message-Id: <bf8d945ea1b423786d7802bbcf769517d1fd01f8.1575330463.git.dirty@apple.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
More accurately match SDM when setting CR0 and PDPTE registers.
Clear PDPTE registers when resetting vcpus.
Signed-off-by: Cameron Esfahani <dirty@apple.com>
Message-Id: <464adb39c8699fb8331d8ad6016fc3e2eff53dbc.1574625592.git.dirty@apple.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In real x86 processors, the REX prefix must come after legacy prefixes.
REX before legacy is ignored. Update the HVF emulation code to properly
handle this. Fix some spelling errors in constants. Fix some decoder
table initialization issues found by Coverity.
Signed-off-by: Cameron Esfahani <dirty@apple.com>
Message-Id: <eff30ded8307471936bec5d84c3b6efbc95e3211.1574625592.git.dirty@apple.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The existing code in QEMU's HVF support to attempt to synchronize TSC
across multiple cores is not sufficient. TSC value on other cores
can go backwards. Until implementation is fixed, remove calls to
hv_vm_sync_tsc(). Pass through TSC to guest OS.
Signed-off-by: Cameron Esfahani <dirty@apple.com>
Message-Id: <44c4afd2301b8bf99682b229b0796d84edd6d66f.1574625592.git.dirty@apple.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If an area is non-RAM and non-ROMD, then remove mappings so accesses
will trap and can be emulated. Change hvf_find_overlap_slot() to take
a size instead of an end address: it wouldn't return a slot because
callers would pass the same address for start and end. Don't always
map area as read/write/execute, respect area flags.
Signed-off-by: Cameron Esfahani <dirty@apple.com>
Message-Id: <1d8476c8f86959273fbdf23c86f8b4b611f5e2e1.1574625592.git.dirty@apple.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Drop the duplicated definition of cpuid AVX512_VBMI macro and rename
it as CPUID_7_0_ECX_AVX512_VBMI. Rename CPUID_7_0_ECX_VBMI2 as
CPUID_7_0_ECX_AVX512_VBMI2.
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Tao Xu <tao3.xu@intel.com>
Message-Id: <20190926021055.6970-3-tao3.xu@intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
sysemu/sysemu.h is a rather unfocused dumping ground for stuff related
to the system-emulator. Evidence:
* It's included widely: in my "build everything" tree, changing
sysemu/sysemu.h still triggers a recompile of some 1100 out of 6600
objects (not counting tests and objects that don't depend on
qemu/osdep.h, down from 5400 due to the previous two commits).
* It pulls in more than a dozen additional headers.
Split stuff related to run state management into its own header
sysemu/runstate.h.
Touching sysemu/sysemu.h now recompiles some 850 objects. qemu/uuid.h
also drops from 1100 to 850, and qapi/qapi-types-run-state.h from 4400
to 4200. Touching new sysemu/runstate.h recompiles some 500 objects.
Since I'm touching MAINTAINERS to add sysemu/runstate.h anyway, also
add qemu/main-loop.h.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-30-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[Unbreak OS-X build]
In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
Almost a third of its inclusions are actually superfluous. Delete
them. Downgrade two more to qapi/qapi-types-run-state.h, and move one
from char/serial.h to char/serial.c.
hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and
stubs/semihost.c define variables declared in sysemu/sysemu.h without
including it. The compiler is cool with that, but include it anyway.
This doesn't reduce actual use much, as it's still included into
widely included headers. The next commit will tackle that.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-27-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
hw/boards.h pulls in almost 60 headers. The less we include it into
headers, the better. As a first step, drop superfluous inclusions,
and downgrade some more to what's actually needed. Gets rid of just
one inclusion into a header.
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-23-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Kernel commit c4f55198c7c2 ("kvm: x86: Introduce KVM_CAP_EXCEPTION_PAYLOAD")
introduced a new KVM capability which allows userspace to correctly
distinguish between pending and injected exceptions.
This distinguish is important in case of nested virtualization scenarios
because a L2 pending exception can still be intercepted by the L1 hypervisor
while a L2 injected exception cannot.
Furthermore, when an exception is attempted to be injected by QEMU,
QEMU should specify the exception payload (CR2 in case of #PF or
DR6 in case of #DB) instead of having the payload already delivered in
the respective vCPU register. Because in case exception is injected to
L2 guest and is intercepted by L1 hypervisor, then payload needs to be
reported to L1 intercept (VMExit handler) while still preserving
respective vCPU register unchanged.
This commit adds support for QEMU to properly utilise this new KVM
capability (KVM_CAP_EXCEPTION_PAYLOAD).
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Message-Id: <20190619162140.133674-10-liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that we have both ArchCPU and CPUArchState, we can define
this generically instead of via macro in each target's cpu.h.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In target/i386/hvf/hvf.c, a break statement was probably missing in
`hvf_vcpu_exec()`, in handling EXIT_REASON_HLT.
These lines seemed to be equivalent to `kvm_handle_halt()`.
Signed-off-by: Chen Zhang <tgfbeta@me.com>
Message-Id: <087F1D9C-109D-41D1-BE2C-CE5D840C981B@me.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We commonly define the header guard symbol without an explicit value.
Normalize the exceptions.
Done with scripts/clean-header-guards.pl.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190315145123.28030-8-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Leading underscores are ill-advised because such identifiers are
reserved. Trailing underscores are merely ugly. Strip both.
Our header guards commonly end in _H. Normalize the exceptions.
Done with scripts/clean-header-guards.pl.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190315145123.28030-7-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Changes to slirp/ dropped, as we're about to spin it off]
Header guard symbols should match their file name to make guard
collisions less likely.
Cleaned up with scripts/clean-header-guards.pl, followed by some
renaming of new guard symbols picked by the script to better ones.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190315145123.28030-6-armbru@redhat.com>
[Rebase to master: update include/hw/net/ne2000-isa.h]
The machine that with hvf accelerator and smp sometimes boot hangs
because all processors are executing instructions at startup,
including early I/O emulations. We should just allow the bootstrap
processor to initialize the machine and then to wake up slave
processors by interrupt.
Signed-off-by: Heiher <r@hev.cc>
Message-Id: <20190123073402.28465-1-r@hev.cc>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In 16-bit addressing mode, when Mod = 0 and R/M = 6, decoded displacement
doesn't reach decode_linear_addr and gets lost. Instructions that
involve the combination of ModRM always get a pointer with zero offset
from the beginning of DS segment.
The change fixes drawing in F-BIRD from day 1 of '18 advent calendar.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20190125154743.14498-1-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
MPX support is being phased out by Intel and actually I am not sure that
OS X has ever enabled it in XCR0. Drop it from the Hypervisor.framework
acceleration.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some files claim that the code is licensed under the GPL, but then
suddenly suggest that the user should have a look at the LGPL.
That's of course non-sense, replace it with the correct GPL wording
instead.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1548255083-8190-1-git-send-email-thuth@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
It's going to clutter QEMU logs if 0x0f00 is trapped.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20181203100415.53027-2-r.bolshakov@yadro.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Single opcode instructions in ff group were incorrectly processed
because an overrun of _decode_tbl1[0xff] resulted in access of
_decode_tbl2[0x0]. Thus, decode_sldtgroup was called instead of
decode_ffgroup:
7d71: decode_sldtgroup: 1
Unimplemented handler (7d71) for 108 (ff 0)
While at it correct maximum length for _decode_tbl2 and _decode_tbl3.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
accel_init_machine sets *(acc->allowed) to true if acc->init_machine(ms)
succeeds. There's no need to have both hvf_allowed and hvf_disabled.
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20181018143051.48508-1-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
According to Intel(R)64 and IA-32 Architectures Software Developer's
Manual, the following one-byte registers should be fetched when REX
prefix is present (sorted by reg encoding index):
AL, CL, DL, BL, SPL, BPL, SIL, DIL, R8L - R15L
The first 8 are fetched if REX.R is zero, the last 8 if non-zero.
The following registers should be fetched for instructions without REX
prefix (also sorted by reg encoding index):
AL, CL, DL, BL, AH, CH, DH, BH
Current emulation code doesn't handle accesses to SPL, BPL, SIL, DIL
when REX is present, thefore an instruction 40883e "mov %dil,(%rsi)" is
decoded as "mov %bh,(%rsi)".
That caused an infinite loop in vp_reset:
https://lists.gnu.org/archive/html/qemu-devel/2018-10/msg03293.html
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20181018134401.44471-1-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
While at it, also rename var to indicate it is not used only in KVM.
Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com>
Reviewed-by: Patrick Colp <patrick.colp@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Message-Id: <20180914003827.124570-2-liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
