From: "Alex Bennée" <alex.bennee@linaro.org>
To: Alvise Rigo <a.rigo@virtualopensystems.com>
Cc: mttcg@listserver.greensocs.com, claudio.fontana@huawei.com,
qemu-devel@nongnu.org, pbonzini@redhat.com,
jani.kokkonen@huawei.com, tech@virtualopensystems.com,
rth@twiddle.net
Subject: Re: [Qemu-devel] [RFC v7 12/16] configure: Use slow-path for atomic only when the softmmu is enabled
Date: Thu, 18 Feb 2016 16:43:00 +0000 [thread overview]
Message-ID: <87ziuyc6ln.fsf@linaro.org> (raw)
In-Reply-To: <871t8adlab.fsf@linaro.org>
Alex Bennée <alex.bennee@linaro.org> writes:
> Alvise Rigo <a.rigo@virtualopensystems.com> writes:
>
>> Use the new slow path for atomic instruction translation when the
>> softmmu is enabled.
>>
>> At the moment only arm and aarch64 use the new LL/SC backend. It is
>> possible to disable such backed with --disable-arm-llsc-backend.
>
> Do we want to disable the backend once it is merged? Does it serve a
> purpose other than to confuse the user?
Also this needs to be after the actual implementation has been filled in
or you'll have a broken build!
>
>>
>> Suggested-by: Jani Kokkonen <jani.kokkonen@huawei.com>
>> Suggested-by: Claudio Fontana <claudio.fontana@huawei.com>
>> Signed-off-by: Alvise Rigo <a.rigo@virtualopensystems.com>
>> ---
>> configure | 14 ++++++++++++++
>> 1 file changed, 14 insertions(+)
>>
>> diff --git a/configure b/configure
>> index 44ac9ab..915efcc 100755
>> --- a/configure
>> +++ b/configure
>> @@ -294,6 +294,7 @@ solaris="no"
>> profiler="no"
>> cocoa="no"
>> softmmu="yes"
>> +arm_tcg_use_llsc="yes"
>> linux_user="no"
>> bsd_user="no"
>> aix="no"
>> @@ -880,6 +881,10 @@ for opt do
>> ;;
>> --disable-debug-tcg) debug_tcg="no"
>> ;;
>> + --enable-arm-llsc-backend) arm_tcg_use_llsc="yes"
>> + ;;
>> + --disable-arm-llsc-backend) arm_tcg_use_llsc="no"
>> + ;;
>> --enable-debug)
>> # Enable debugging options that aren't excessively noisy
>> debug_tcg="yes"
>> @@ -4751,6 +4756,7 @@ echo "host CPU $cpu"
>> echo "host big endian $bigendian"
>> echo "target list $target_list"
>> echo "tcg debug enabled $debug_tcg"
>> +echo "arm use llsc backend" $arm_tcg_use_llsc
>> echo "gprof enabled $gprof"
>> echo "sparse enabled $sparse"
>> echo "strip binaries $strip_opt"
>> @@ -4806,6 +4812,7 @@ echo "Install blobs $blobs"
>> echo "KVM support $kvm"
>> echo "RDMA support $rdma"
>> echo "TCG interpreter $tcg_interpreter"
>> +echo "use ld/st excl $softmmu"
>
> I think we can drop everything above here.
>
>> echo "fdt support $fdt"
>> echo "preadv support $preadv"
>> echo "fdatasync $fdatasync"
>> @@ -5863,6 +5870,13 @@ fi
>> echo "LDFLAGS+=$ldflags" >> $config_target_mak
>> echo "QEMU_CFLAGS+=$cflags" >> $config_target_mak
>>
>> +# Use tcg LL/SC tcg backend for exclusive instruction is arm/aarch64
>> +# softmmus targets
>> +if test "$arm_tcg_use_llsc" = "yes" ; then
>> + if test "$target" = "arm-softmmu" ; then
>> + echo "CONFIG_ARM_USE_LDST_EXCL=y" >> $config_target_mak
>> + fi
>> +fi
>
> This isn't going to be just ARM specific and it will be progressively
> turned on for other arches. So perhaps with the CONFIG_SOFTMMU section:
>
> if test "$target_softmmu" = "yes" ; then
> echo "CONFIG_SOFTMMU=y" >> $config_target_mak
>
> # Use SoftMMU LL/SC primitives?
> case "$target_name" in
> arm | aarch64)
> echo "CONFIG_USE_LDST_EXCL=y" >> $config_target_mak
> ;;
> esac
> fi
>
>
>> done # for target in $targets
>>
>> if [ "$pixman" = "internal" ]; then
--
Alex Bennée
next prev parent reply other threads:[~2016-02-18 16:43 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-29 9:32 [Qemu-devel] [RFC v7 00/16] Slow-path for atomic instruction translation Alvise Rigo
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 01/16] exec.c: Add new exclusive bitmap to ram_list Alvise Rigo
2016-02-11 13:00 ` Alex Bennée
2016-02-11 13:21 ` alvise rigo
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 02/16] softmmu: Simplify helper_*_st_name, wrap unaligned code Alvise Rigo
2016-02-11 13:07 ` Alex Bennée
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 03/16] softmmu: Simplify helper_*_st_name, wrap MMIO code Alvise Rigo
2016-02-11 13:15 ` Alex Bennée
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 04/16] softmmu: Simplify helper_*_st_name, wrap RAM code Alvise Rigo
2016-02-11 13:18 ` Alex Bennée
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 05/16] softmmu: Add new TLB_EXCL flag Alvise Rigo
2016-02-11 13:18 ` Alex Bennée
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 06/16] qom: cpu: Add CPUClass hooks for exclusive range Alvise Rigo
2016-02-11 13:22 ` Alex Bennée
2016-02-18 13:53 ` alvise rigo
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 07/16] softmmu: Add helpers for a new slowpath Alvise Rigo
2016-02-11 16:33 ` Alex Bennée
2016-02-18 13:58 ` alvise rigo
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 08/16] softmmu: Honor the new exclusive bitmap Alvise Rigo
2016-02-16 17:39 ` Alex Bennée
2016-02-18 14:18 ` alvise rigo
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 09/16] softmmu: Include MMIO/invalid exclusive accesses Alvise Rigo
2016-02-16 17:49 ` Alex Bennée
2016-02-18 14:18 ` alvise rigo
2016-02-18 16:26 ` Alex Bennée
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 10/16] softmmu: Protect MMIO exclusive range Alvise Rigo
2016-02-17 18:55 ` Alex Bennée
2016-02-18 14:15 ` alvise rigo
2016-02-18 16:25 ` Alex Bennée
2016-03-07 18:13 ` alvise rigo
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 11/16] tcg: Create new runtime helpers for excl accesses Alvise Rigo
2016-02-18 16:16 ` Alex Bennée
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 12/16] configure: Use slow-path for atomic only when the softmmu is enabled Alvise Rigo
2016-02-18 16:40 ` Alex Bennée
2016-02-18 16:43 ` Alex Bennée [this message]
2016-03-07 17:21 ` alvise rigo
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 13/16] softmmu: Add history of excl accesses Alvise Rigo
2016-02-16 17:07 ` Alex Bennée
2016-02-18 14:17 ` alvise rigo
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 14/16] target-arm: translate: Use ld/st excl for atomic insns Alvise Rigo
2016-02-18 17:02 ` Alex Bennée
2016-03-07 18:39 ` alvise rigo
2016-03-07 20:06 ` Alex Bennée
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 15/16] target-arm: cpu64: use custom set_excl hook Alvise Rigo
2016-02-18 18:19 ` Alex Bennée
2016-01-29 9:32 ` [Qemu-devel] [RFC v7 16/16] target-arm: aarch64: add atomic instructions Alvise Rigo
2016-02-19 11:34 ` Alex Bennée
2016-02-19 11:44 ` [Qemu-devel] [RFC v7 00/16] Slow-path for atomic instruction translation Alex Bennée
2016-02-19 12:01 ` alvise rigo
2016-02-19 12:19 ` Alex Bennée
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