For A64, any input to an indirect branch can cause this.
For A32, many indirect branch paths force the branch to be aligned,
but BXWritePC does not. This includes the BX instruction but also
other interworking changes to PC. Prior to v8, this case is UNDEFINED.
With v8, this is CONSTRAINED UNPREDICTABLE and may either raise an
exception or force align the PC.
We choose to raise an exception because we have the infrastructure,
it makes the generated code for gen_bx simpler, and it has the
possibility of catching more guest bugs.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We will reuse this section of arm_deliver_fault for
raising pc alignment faults.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Because of the complexity of setting ESR, re-use the existing
arm_cpu_do_unaligned_access function. This means we have to
handle the exception ourselves in cpu_loop, transforming it
to the appropriate signal.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Because of the complexity of setting ESR, continue to use
arm_deliver_fault. This means we cannot remove the code
within cpu_loop that decodes EXCP_DATA_ABORT and
EXCP_PREFETCH_ABORT.
But using the new hook means that we don't have to do the
page_get_flags check manually, and we'll be able to restrict
the tlb_fill hook to sysemu later.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Pretend the fault always happens at page table level 3.
Failure to set this leaves level = 0, which is impossible for
ARMFault_Permission, and produces an invalid syndrome, which
reaches g_assert_not_reached in cpu_loop.
Fixes: 8db94ab4e5 ("linux-user/aarch64: Pass syndrome to EXC_*_ABORT")
Reported-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20210320000606.1788699-1-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
A proper syndrome is required to fill in the proper si_code.
Use page_get_flags to determine permission vs translation for user-only.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-27-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This "bit" is a particular value of the page's MemAttr.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200626033144.790098-43-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We need to check the memattr of a page in order to determine
whether it is Tagged for MTE. Between Stage1 and Stage2,
this becomes simpler if we always collect this data, instead
of occasionally being presented with NULL.
Use the nonnull attribute to allow the compiler to check that
all pointer arguments are non-null.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200626033144.790098-42-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Use the same code as system mode, so that we generate the same
exception + syndrome for the unaligned access.
For the moment, if MTE is enabled so that this path is reachable,
this would generate a SIGSEGV in the user-only cpu_loop. Decoding
the syndrome to produce the proper SIGBUS will be done later.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200626033144.790098-15-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Add a SIGBUS signal handler. In this handler, it checks the SIGBUS type,
translates the host VA delivered by host to guest PA, then fills this PA
to guest APEI GHES memory, then notifies guest according to the SIGBUS
type.
When guest accesses the poisoned memory, it will generate a Synchronous
External Abort(SEA). Then host kernel gets an APEI notification and calls
memory_failure() to unmapped the affected page in stage 2, finally
returns to guest.
Guest continues to access the PG_hwpoison page, it will trap to KVM as
stage2 fault, then a SIGBUS_MCEERR_AR synchronous signal is delivered to
Qemu, Qemu records this error address into guest APEI GHES memory and
notifes guest using Synchronous-External-Abort(SEA).
In order to inject a vSEA, we introduce the kvm_inject_arm_sea() function
in which we can setup the type of exception and the syndrome information.
When switching to guest, the target vcpu will jump to the synchronous
external abort vector table entry.
The ESR_ELx.DFSC is set to synchronous external abort(0x10), and the
ESR_ELx.FnV is set to not valid(0x1), which will tell guest that FAR is
not valid and hold an UNKNOWN value. These values will be set to KVM
register structures through KVM_SET_ONE_REG IOCTL.
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-id: 20200512030609.19593-10-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The IL bit is set for 32-bit instructions, thus passing false
with the is_16bit parameter to syn_data_abort_with_iss() makes
a syn mask that always has the IL bit set.
Pass is_16bit as true to make the initial syn mask have IL=0,
so that the final IL value comes from or'ing template_syn.
Cc: qemu-stable@nongnu.org
Fixes: aaa1f954d4 ("target-arm: A64: Create Instruction Syndromes for Data Aborts")
Signed-off-by: Jeff Kubascik <jeff.kubascik@dornerworks.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200117004618.2742-2-richard.henderson@linaro.org
[rth: Extracted this as a self-contained bug fix from a larger patch]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
These routines are TCG specific.
The arm_deliver_fault() function is only used within the new
helper. Make it static.
Suggested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190701132516.26392-13-philmd@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
