In the accessor functions ld*_he_p() and st*_he_p() we use memcpy()
to perform a load or store to a pointer which might not be aligned
for the size of the type. We rely on the compiler to optimize this
memcpy() into an efficient load or store instruction where possible.
This is required for good performance, but at the moment it is also
required for correct operation, because some users of these functions
require that the access is atomic if the pointer is aligned, which
will only be the case if the compiler has optimized out the memcpy().
(The particular example where we discovered this is the virtio
vring_avail_idx() which calls virtio_lduw_phys_cached() which
eventually ends up calling lduw_he_p().)
Unfortunately some compile environments, such as the fortify-source
setup used in Alpine Linux, define memcpy() to a wrapper function
in a way that inhibits this compiler optimization.
The correct long-term fix here is to add a set of functions for
doing atomic accesses into AddressSpaces (and to other relevant
families of accessor functions like the virtio_*_phys_cached()
ones), and make sure that callsites which want atomic behaviour
use the correct functions.
In the meantime, switch to using __builtin_memcpy() in the
bswap.h accessor functions. This will make us robust against things
like this fortify library in the short term. In the longer term
it will mean that we don't end up with these functions being really
badly-performing even if the semantics of the out-of-line memcpy()
are correct.
Fix a TCG crash due to attempting an atomic increment
operation without having set up the address first.
This is a similar case to that dealt with in commit
e84fcd7f662a0d8198703, and we fix it in the same way.
Fixes: https://bugs.launchpad.net/qemu/+bug/1807675
Backports commit 8cb2ca3d7479748587313f0b34034a3f8aa08c92 from qemu
This ensures that softmmu directories are culled after a
"./configure --target-list=x86_64-linux-user".
Backports commit b7c11e574977a0addfbbdb89377c6f52affe64ec from qemu
Currently, a callback registered through the RAMBlock notifier
is not able to get the memory region type (i.e callback is not
able to use memory_region_is_ram_device function). This is
because mr->ram assignment happens _after_ the memory is allocated
whereas the callback is executed during allocation.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1667249
Backports commit 2ddb89b00f947f785c9ca6742f28f954e3b75e62 from qemu
While running the GCC test suite against 4.0.0-rc0, Kito found a
regression introduced by the decodetree conversion that caused divuw and
remuw to sign-extend their inputs. The ISA manual says they are
supposed to be zero extended:
DIVW and DIVUW instructions are only valid for RV64, and divide the
lower 32 bits of rs1 by the lower 32 bits of rs2, treating them as
signed and unsigned integers respectively, placing the 32-bit
quotient in rd, sign-extended to 64 bits. REMW and REMUW
instructions are only valid for RV64, and provide the corresponding
signed and unsigned remainder operations respectively. Both REMW
and REMUW always sign-extend the 32-bit result to 64 bits, including
on a divide by zero.
Here's Kito's reduced test case from the GCC test suite
unsigned calc_mp(unsigned mod)
{
unsigned a,b,c;
c=-1;
a=c/mod;
b=0-a*mod;
if (b > mod) { a += 1; b-=mod; }
return b;
}
int main(int argc, char *argv[])
{
unsigned x = 1234;
unsigned y = calc_mp(x);
if ((sizeof (y) == 4 && y != 680)
|| (sizeof (y) == 2 && y != 134))
abort ();
exit (0);
}
I haven't done any other testing on this, but it does fix the test case.
Backports commit f17e02cd3731bdfe2942d1d0b2a92f26da02408c from qemu
cortex-a7 and cortex-a15 have pmus (PMUv2) and they advertise
them in ID_DFR0. Let's allow them to function. This also enables
the pmu cpu property to work with these cpu types, i.e. we can
now do '-cpu cortex-a15,pmu=off' to remove the pmu.
Backports commit a46118fc16537a593119e5b316052a98514046bb from qemu
Fix a QEMU NULL derefence that occurs when the guest attempts to
enable PMU counters with a non-v8 cpu model or a v8 cpu model
which has not configured a PMU.
Backports commit cbbb3041fe2f57a475cef5d6b0ef836118aad106 from qemu
The second word has been loaded from the unincremented
address since the first commit.
Backports commit a036f5302c13634f3d375615b2949fd1fa1657b6 from qemu
Currently, the Cascadelake-Server, Icelake-Client, and
Icelake-Server are always generating the following warning:
qemu-system-x86_64: warning: \
host doesn't support requested feature: CPUID.07H:ECX [bit 4]
This happens because OSPKE was never returned by
GET_SUPPORTED_CPUID or x86_cpu_get_supported_feature_word().
OSPKE is a runtime flag automatically set by the KVM module or by
TCG code, was always cleared by x86_cpu_filter_features(), and
was not supposed to appear on the CPU model table.
Remove the OSPKE flag from the CPU model table entries, to avoid
the bogus warning and avoid returning invalid feature data on
query-cpu-* QMP commands. As OSPKE was always cleared by
x86_cpu_filter_features(), this won't have any guest-visible
impact.
Include a test case that should detect the problem if we introduce
a similar bug again.
Fixes: c7a88b52f62b ("i386: Add new model of Cascadelake-Server")
Fixes: 8a11c62da914 ("i386: Add new CPU model Icelake-{Server,Client}")
Backports commit bb4928c7cafe50ab2137a0034e350ef1bfa044d9 from qemu
Now that kvm_arch_get_supported_cpuid() will only return
arch_capabilities if QEMU is able to initialize the MSR properly,
we know that the feature is safely migratable.
Backports commit 014018e19b3c54dd1bf5072bc912ceffea40abe8 from qemu
If vectored interrupts are enabled (bits[1:0]
of mtvec/stvec == 1) then use the following
logic for trap entry address calculation:
pc = mtvec + cause * 4
In addition to adding support for vectored interrupts
this patch simplifies the interrupt delivery logic
by making sync/async cause decoding and encoding
steps distinct.
The cause code and the sign bit indicating sync/async
is split at the beginning of the function and fixed
cause is renamed to cause. The MSB setting for async
traps is delayed until setting mcause/scause to allow
redundant variables to be eliminated. Some variables
are renamed for conciseness and moved so that decls
are at the start of the block.
Backports commit acbbb94e5730c9808830938e869d243014e2923a from qemu
This effectively changes riscv_cpu_update_mip
from edge to level. i.e. cpu_interrupt or
cpu_reset_interrupt are called regardless of
the current interrupt level.
Fixes WFI doesn't return when a IPI is issued:
- https://github.com/riscv/riscv-qemu/issues/132
To test:
1) Apply RISC-V Linux CPU hotplug patch:
- http://lists.infradead.org/pipermail/linux-riscv/2018-May/000603.html
2) Enable CONFIG_CPU_HOTPLUG in linux .config
3) Try to offline and online cpus:
echo 1 > /sys/devices/system/cpu/cpu2/online
echo 0 > /sys/devices/system/cpu/cpu2/online
echo 1 > /sys/devices/system/cpu/cpu2/online
Backports commit d26f5a423438e579d3ff0ca35e44edb966a36233 from qemu
This change checks elf_flags for EF_RISCV_RVE and if
present uses the RVE linux syscall ABI which uses t0
for the syscall number instead of a7.
Warn and exit if a non-RVE ABI binary is run on a
cpu with the RVE extension as it is incompatible.
Backports relevant parts of 5836c3eccedb6dfab16b8f606f2de24b8938b69c
from qemu
We can't allow the supervisor to control SEIP as this would allow the
supervisor to clear a pending external interrupt which will result in
lost a interrupt in the case a PLIC is attached. The SEIP bit must be
hardware controlled when a PLIC is attached.
This logic was previously hard-coded so SEIP was always masked even
if no PLIC was attached. This patch adds riscv_cpu_claim_interrupts
so that the PLIC can register control of SEIP. In the case of models
without a PLIC (spike), the SEIP bit remains software controlled.
This interface allows for hardware control of supervisor timer and
software interrupts by other interrupt controller models.
Backports commit e3e7039cc24ecf47d81c091e8bb04552d6564ad8 from qemu
Add a debugger field to CPURISCVState. Add riscv_csrrw_debug function
to set it. Disable mode checks when debugger field true.
Backports commit 753e3fe207db08ce0ef0405e8452c3397c9b9308 from qemu
This adds some missing CSR_* register macros, and documents some as being
priv v1.9.1 specific.
Backports commit 8e73df6aa3f2f0e5c26c03a94a88406616291815 from qemu
during the refactor to decodetree we removed the manual decoding that is
necessary for c.jal/c.addiw and removed the translation of c.flw/c.ld
and c.fsw/c.sd. This reintroduces the manual parsing and the
omited implementation.
Backports commit f330433b3633647b047cfa418c2ca4d18fda69c7 from qemu
These instructions do not trap when SVE is disabled in EL0,
causing them to be executed with wrong size information.
Backports commit 5de56742a3c91de3d646326bec43a989bba83ca4 from qemu
Some generic arch timer registers are Config-RW in the EL0,
which means the EL0 exception level can have write permission
if it is appropriately configured.
When VM access registers, QEMU firstly checks whether they have RW
permission, then check whether it is appropriately configured.
If they are defined to read only in EL0, even though they have been
appropriately configured, they still do not have write permission.
So need to add the write permission according to ARMV8 spec when
define it.
Backports commit daf1dc5f82cefe2a57f184d5053e8b274ad2ba9a from qemu
with all 16 bit insns moved to decodetree no path is falling back to
gen_system(), so we can remove it.
Backports commit 8f7bc273868939f0821e07fb23792db63d45bffb from qemu
manual decoding in gen_arith() is not necessary with decodetree. For now
the function is called trans_arith as the original gen_arith still
exists. The former will be renamed to gen_arith as soon as the old
gen_arith can be removed.
Backports commit f2ab1728675772cd475a33f4df3d2f68a22c188f from qemu
gen_arith_imm() does a lot of decoding manually, which was hard to read
in case of the shift instructions and is not necessary anymore with
decodetree.
Backports commit 7a50d3e2ae7f13b24fe55990ea0b8ddcbbb43130 from qemu
With decodetree we don't need to convert RISC-V opcodes into to MemOps
as the old gen_store() did.
Backports commit bce8a342a1f0919479d18ec812b100136daa746b from qemu
With decodetree we don't need to convert RISC-V opcodes into to MemOps
as the old gen_load() did.
Backports commit 98898b20e9cca462843c22ad952c216ffd57d654 from qemu
We now utilizes argument-sets of decodetree such that no manual
decoding is necessary.
Backports commit 090cc2c898a04e42350eabf1bcf7d245471603f9 from qemu
