Use the same flag generation code as SHL and SHR, but use
the existing gen_shiftd_rm_T1 function to compute the result
as well as CC_SRC.
Decoding-wise, SHLD/SHRD by immediate count as a 4 operand
instruction because s->T0 and s->T1 actually occupy three op
slots. The infrastructure used by opcodes in the 0F 3A table
works fine.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SHLD/SHRD can have 3 register operands - s->T0, s->T1 and either
1 or CL - and therefore decode->op[2] is taken by the low part
of the register being shifted. Pass X86_OP_* to gen_shift_count
from its current callers and hardcode cpu_regs[R_ECX] as the
shift count.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use gen_ld_modrm/gen_st_modrm, moving them and gen_shift_flags to the
caller. This way, gen_shiftd_rm_T1 becomes something that the new
decoder can call.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
These have very simple generators and no need for complex group
decoding. Apart from LAR/LSL which are simplified to use
gen_op_deposit_reg_v and movcond, the code is generally lifted
from translate.c into the generators.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SYSENTER is allowed in VM86 mode, but not in real mode. Split the check
so that PE and !VM86 are covered by separate bits.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is already partly implemented due to VLDMXCSR and VSTMXCSR; finish
the job.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All other control registers are stored plainly in CPUX86State.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is a bit more generic, as it can be applied to MPX as well.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Just like X86_ENTRYr, X86_ENTRYwr is easily changed to use only T0.
In this case, the motivation is to use it for the MOV instruction
family. The case when you need to preserve the input value is the
odd one, as it is used basically only for BLS* instructions.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
I am not sure why I made it use T1. It is a bit more symmetric with
respect to X86_ENTRYwr (which uses T0 for the "w"ritten operand
and T1 for the "r"ead operand), but it is also less flexible because it
does not let you apply zextT0/sextT0.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This makes for easier cpu_cc_* setup, and not using set_cc_op()
should come in handy if QEMU ever implements APX.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Avoid using set_cc_op() in preparation for implementing APX; treat
CC_OP_EFLAGS similar to the case where we have the "opposite" cc_op
(CC_OP_ADOX for ADCX and CC_OP_ADCX for ADOX), except the resulting
cc_op is not CC_OP_ADCOX. This is written easily as two "if"s, whose
conditions are both false for CC_OP_EFLAGS, both true for CC_OP_ADCOX,
and one each true for CC_OP_ADCX/ADOX.
The new logic also makes it easy to drop usage of tmp0.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
CPUX86State argument would only be used to fetch bytes, but that has to be
done before the generator function is called. So remove it, and all
temptation together with it.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fixes Coverity CID 1546885.
Fixes: 16dcf200dc ("i386/sev: Introduce "sev-common" type to encapsulate common SEV state")
Signed-off-by: Pankaj Gupta <pankaj.gupta@amd.com>
Message-ID: <20240607183611.1111100-4-pankaj.gupta@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Set 'finish->id_block_en' early, so that it is properly reset.
Fixes coverity CID 1546887.
Fixes: 7b34df4426 ("i386/sev: Introduce 'sev-snp-guest' object")
Signed-off-by: Pankaj Gupta <pankaj.gupta@amd.com>
Message-ID: <20240607183611.1111100-2-pankaj.gupta@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When QEMU is started with:
-cpu host,host-cache-info=on,l3-cache=off \
-smp 2,sockets=1,dies=1,cores=1,threads=2
Guest can't acquire maximum number of addressable IDs for processor cores in
the physical package from CPUID[04H].
When creating a CPU topology of 1 core per package, host-cache-info only
uses the Host's addressable core IDs field (CPUID.04H.EAX[bits 31-26]),
resulting in a conflict (on the multicore Host) between the Guest core
topology information in this field and the Guest's actual cores number.
Fix it by removing the unnecessary condition to cover 1 core per package
case. This is safe because cores_per_pkg will not be 0 and will be at
least 1.
Fixes: d7caf13b5f ("x86: cpu: fixup number of addressable IDs for logical processors sharing cache")
Signed-off-by: Guixiong Wei <weiguixiong@bytedance.com>
Signed-off-by: Yipeng Yin <yinyipeng@bytedance.com>
Signed-off-by: Chuang Xu <xuchuangxclwt@bytedance.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-ID: <20240611032314.64076-1-xuchuangxclwt@bytedance.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add cpuid bit definition for overflow recovery. This is needed in the case
where a deferred error has been sent to the guest, a guest process accesses the
poisoned memory, but the machine_check_poll function has not yet handled the
original deferred error. If overflow recovery is not set in this case, when we
handle the uncorrected error from the poisoned memory access, the overflow bit
will be set and will result in the guest being shut down.
By the time the MCE reaches the guest, the overflow has been handled
by the host and has not caused a shutdown, so include the bit unconditionally.
Signed-off-by: John Allen <john.allen@amd.com>
Message-ID: <20240603193622.47156-4-john.allen@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add cpuid bit definition for the SUCCOR feature. This cpuid bit is required to
be exposed to guests to allow them to handle machine check exceptions on AMD
hosts.
----
v2:
- Add "succor" feature word.
- Add case to kvm_arch_get_supported_cpuid for the SUCCOR feature.
Reported-by: William Roche <william.roche@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: John Allen <john.allen@amd.com>
Message-ID: <20240603193622.47156-3-john.allen@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For the most part, AMD hosts can use the same MCE injection code as Intel, but
there are instances where the qemu implementation is Intel specific. First, MCE
delivery works differently on AMD and does not support broadcast. Second,
kvm_mce_inject generates MCEs that include a number of Intel specific status
bits. Modify kvm_mce_inject to properly generate MCEs on AMD platforms.
Reported-by: William Roche <william.roche@oracle.com>
Signed-off-by: John Allen <john.allen@amd.com>
Message-ID: <20240603193622.47156-2-john.allen@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
FRED CPU states are managed in 9 new FRED MSRs, in addtion to a few
existing CPU registers and MSRs, e.g., CR4.FRED and MSR_IA32_PL0_SSP.
Save/restore/migrate FRED MSRs if FRED is exposed to the guest.
Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Message-ID: <20231109072012.8078-7-xin3.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allow VMX nested-exception support to be exposed in KVM guests, thus
nested KVM guests can enumerate it.
Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Message-ID: <20231109072012.8078-6-xin3.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The CR4.FRED bit, i.e., CR4[32], is no longer a reserved bit when FRED
is exposed to guests, otherwise it is still a reserved bit.
Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-ID: <20231109072012.8078-3-xin3.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
FRED, i.e., the Intel flexible return and event delivery architecture,
defines simple new transitions that change privilege level (ring
transitions).
The new transitions defined by the FRED architecture are FRED event
delivery and, for returning from events, two FRED return instructions.
FRED event delivery can effect a transition from ring 3 to ring 0, but
it is used also to deliver events incident to ring 0. One FRED
instruction (ERETU) effects a return from ring 0 to ring 3, while the
other (ERETS) returns while remaining in ring 0. Collectively, FRED
event delivery and the FRED return instructions are FRED transitions.
In addition to these transitions, the FRED architecture defines a new
instruction (LKGS) for managing the state of the GS segment register.
The LKGS instruction can be used by 64-bit operating systems that do
not use the new FRED transitions.
WRMSRNS is an instruction that behaves exactly like WRMSR, with the
only difference being that it is not a serializing instruction by
default. Under certain conditions, WRMSRNS may replace WRMSR to improve
performance. FRED uses it to switch RSP0 in a faster manner.
Search for the latest FRED spec in most search engines with this search
pattern:
site:intel.com FRED (flexible return and event delivery) specification
The CPUID feature flag CPUID.(EAX=7,ECX=1):EAX[17] enumerates FRED, and
the CPUID feature flag CPUID.(EAX=7,ECX=1):EAX[18] enumerates LKGS, and
the CPUID feature flag CPUID.(EAX=7,ECX=1):EAX[19] enumerates WRMSRNS.
Add CPUID definitions for FRED/LKGS/WRMSRNS, and expose them to KVM guests.
Because FRED relies on LKGS and WRMSRNS, add that to feature dependency
map.
Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Message-ID: <20231109072012.8078-2-xin3.li@intel.com>
[Fix order of dependencies, add dependencies from LM to FRED. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
macOS 10.15 introduced the more efficient hv_vcpu_run_until() function
to supersede hv_vcpu_run(). According to the documentation, there is no
longer any reason to use the latter on modern host OS versions, especially
after 11.0 added support for an indefinite deadline.
Observed behaviour of the newer function is that as documented, it exits
much less frequently - and most of the original function’s exits seem to
have been effectively pointless.
Another reason to use the new function is that it is a prerequisite for
using newer features such as in-kernel APIC support. (Not covered by
this patch.)
This change implements the upgrade by selecting one of three code paths
at compile time: two static code paths for the new and old functions
respectively, when building for targets where the new function is either
not available, or where the built executable won’t run on older
platforms lacking the new function anyway. The third code path selects
dynamically based on runtime detected availability of the weakly-linked
symbol.
Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Message-ID: <20240605112556.43193-7-phil@philjordan.eu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When interrupting a vCPU thread, this patch actually tells the hypervisor to
stop running guest code on that vCPU.
Calling hv_vcpu_interrupt actually forces a vCPU exit, analogously to
hv_vcpus_exit on aarch64. Alternatively, if the vCPU thread
is not
running the VM, it will immediately cause an exit when it attempts
to do so.
Previously, hvf_kick_vcpu_thread relied upon hv_vcpu_run returning very
frequently, including many spurious exits, which made it less of a problem that
nothing was actively done to stop the vCPU thread running guest code.
The newer, more efficient hv_vcpu_run_until exits much more rarely, so a true
"kick" is needed before switching to that.
Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Message-ID: <20240605112556.43193-6-phil@philjordan.eu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When using x86 macOS Hypervisor.framework as accelerator, detection of
dirty memory regions is implemented by marking logged memory region
slots as read-only in the EPT, then setting the dirty flag when a
guest write causes a fault. The area marked dirty should then be marked
writable in order for subsequent writes to succeed without a VM exit.
However, dirty bits are tracked on a per-page basis, whereas the fault
handler was marking the whole logged memory region as writable. This
change fixes the fault handler so only the protection of the single
faulting page is marked as dirty.
(Note: the dirty page tracking appeared to work despite this error
because HVF’s hv_vcpu_run() function generated unnecessary EPT fault
exits, which ended up causing the dirty marking handler to run even
when the memory region had been marked RW. When using
hv_vcpu_run_until(), a change planned for a subsequent commit, these
spurious exits no longer occur, so dirty memory tracking malfunctions.)
Additionally, the dirty page is set to permit code execution, the same
as all other guest memory; changing memory protection from RX to RW not
RWX appears to have been an oversight.
Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Reviewed-by: Roman Bolshakov <roman@roolebo.dev>
Tested-by: Roman Bolshakov <roman@roolebo.dev>
Message-ID: <20240605112556.43193-5-phil@philjordan.eu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A bunch of function definitions used empty parentheses instead of (void) syntax, yielding the following warning when building with clang on macOS:
warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
In addition to fixing these function headers, it also fixes what appears to be a typo causing a variable to be unused after initialisation.
warning: variable 'entry_ctls' set but not used [-Wunused-but-set-variable]
Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Reviewed-by: Roman Bolshakov <roman@roolebo.dev>
Tested-by: Roman Bolshakov <roman@roolebo.dev>
Message-ID: <20240605112556.43193-3-phil@philjordan.eu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds the INVTSC bit to the Hypervisor.framework accelerator's
CPUID bit passthrough allow-list. Previously, specifying +invtsc in the CPU
configuration would fail with the following warning despite the host CPU
advertising the feature:
qemu-system-x86_64: warning: host doesn't support requested feature:
CPUID.80000007H:EDX.invtsc [bit 8]
x86 macOS itself relies on a fixed rate TSC for its own Mach absolute time
timestamp mechanism, so there's no reason we can't enable this bit for guests.
When the feature is enabled, a migration blocker is installed.
Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Reviewed-by: Roman Bolshakov <roman@roolebo.dev>
Tested-by: Roman Bolshakov <roman@roolebo.dev>
Message-ID: <20240605112556.43193-2-phil@philjordan.eu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The calculation of FrameTemp is done using the size indicated by mo_pushpop()
before being written back to EBP, but the final writeback to EBP is done using
the size indicated by mo_stacksize().
In the case where mo_pushpop() is MO_32 and mo_stacksize() is MO_16 then the
final writeback to EBP is done using MO_16 which can leave junk in the top
16-bits of EBP after executing ENTER.
Change the writeback of EBP to use the same size indicated by mo_pushpop() to
ensure that the full value is written back.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2198
Message-ID: <20240606095319.229650-5-mark.cave-ayland@ilande.co.uk>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When OS/2 Warp configures its segment descriptors, many of them are configured with
the P flag clear to allow for a fault-on-demand implementation. In the case where
the stack value is POPped into the segment registers, the SP is incremented before
calling gen_helper_load_seg() to validate the segment descriptor:
IN:
0xffef2c0c: 66 07 popl %es
OP:
ld_i32 loc9,env,$0xfffffffffffffff8
sub_i32 loc9,loc9,$0x1
brcond_i32 loc9,$0x0,lt,$L0
st16_i32 loc9,env,$0xfffffffffffffff8
st8_i32 $0x1,env,$0xfffffffffffffffc
---- 0000000000000c0c 0000000000000000
ext16u_i64 loc0,rsp
add_i64 loc0,loc0,ss_base
ext32u_i64 loc0,loc0
qemu_ld_a64_i64 loc0,loc0,noat+un+leul,5
add_i64 loc3,rsp,$0x4
deposit_i64 rsp,rsp,loc3,$0x0,$0x10
extrl_i64_i32 loc5,loc0
call load_seg,$0x0,$0,env,$0x0,loc5
add_i64 rip,rip,$0x2
ext16u_i64 rip,rip
exit_tb $0x0
set_label $L0
exit_tb $0x7fff58000043
If helper_load_seg() generates a fault when validating the segment descriptor then as
the SP has already been incremented, the topmost word of the stack is overwritten by
the arguments pushed onto the stack by the CPU before taking the fault handler. As a
consequence things rapidly go wrong upon return from the fault handler due to the
corrupted stack.
Update the logic for the existing writeback condition so that a POP into the segment
registers also calls helper_load_seg() first before incrementing the SP, so that if a
fault occurs the SP remains unaltered.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2198
Message-ID: <20240606095319.229650-4-mark.cave-ayland@ilande.co.uk>
Fixes: cc1d28bdbe ("target/i386: move 00-5F opcodes to new decoder", 2024-05-07)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Instead of directly implementing the writeback using gen_op_st_v(), use the
existing gen_writeback() function.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-ID: <20240606095319.229650-3-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This will make subsequent changes a little easier to read.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-ID: <20240606095319.229650-2-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
DISAS_NORETURN suppresses the work normally done by gen_eob(), and therefore
must be used in special cases only. Document them.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
HLT uses DISAS_NORETURN because the corresponding helper calls
cpu_loop_exit(). However, while gen_eob() clears HF_RF_MASK and
synthesizes a #DB exception if single-step is active, none of this is
done by HLT. Note that the single-step trap is generated after the halt
is finished.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
PAUSE uses DISAS_NORETURN because the corresponding helper
calls cpu_loop_exit(). However, while HLT clear HF_INHIBIT_IRQ_MASK
to correctly handle "STI; HLT", the same is missing from PAUSE.
And also gen_eob() clears HF_RF_MASK and synthesizes a #DB exception
if single-step is active; none of this is done by HLT and PAUSE.
Start fixing PAUSE, HLT will follow.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
From vm entry to exit, VMRUN is handled as a single instruction. It
uses DISAS_NORETURN in order to avoid processing TF or RF before
the first instruction executes in the guest. However, the corresponding
handling is missing in vmexit. Add it, and at the same time reorganize
the comments with quotes from the manual about the tasks performed
by a #VMEXIT.
Another gen_eob() task that is missing in VMRUN is preparing the
HF_INHIBIT_IRQ flag for the next instruction, in this case by loading
it from the VMCB control state.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If the required DR7 (either from the VMCB or from the host save
area) disables a breakpoint that was enabled prior to vmentry
or vmexit, it is left enabled and will trigger EXCP_DEBUG.
This causes a spurious #DB on the next crossing of the breakpoint.
To disable it, vmentry/vmexit must use cpu_x86_update_dr7
to load DR7.
Because cpu_x86_update_dr7 takes a 32-bit argument, check
reserved bits prior to calling cpu_x86_update_dr7, and do the
same for DR6 as well for consistency.
This scenario is tested by the "host_rflags" test in kvm-unit-tests.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
DR7.GD triggers a #DB exception on any access to debug registers.
The GD bit is cleared so that the #DB handler itself can access
the debug registers.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use decode.c's support for intercepts, doing the check in TCG-generated
code rather than the helper. This is cleaner because it allows removing
the eip_addend argument to helper_pause(), even though it adds a bit of
bloat for opcode 0x90's new decoding function.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use decode.c's support for intercepts, doing the check in TCG-generated
code rather than the helper. This is cleaner because it allows removing
the eip_addend argument to helper_hlt().
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
ICEBP generates a trap-like exception, while gen_exception() produces
a fault. Resurrect gen_update_eip_next() to implement the desired
semantics.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When preparing an exception stack frame for a fault exception, the value
pushed for RF is 1. Take that into account. The same should be true
of interrupts for repeated string instructions, but the situation there
is complicated.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
