在2021年4月27日周二 下午2:33，Philippe Mathieu-Daudé写道：
> According to the 'MIPS MT Application-Specific Extension' manual:
>
> If the VPE executing the instruction is not a Master VPE,
> with the MVP bit of the VPEConf0 register set, the EVP bit
> is unchanged by the instruction.
>
> Modify the DVPE/EVPE opcodes to only update the MVPControl.EVP bit
> if executed on a master VPE.
>
> Reported-by: Hansni Bu <https://launchpad.net/%7Ehansni/+contactuser>
> Buglink: https://bugs.launchpad.net/qemu/+bug/1926277
> Fixes: f249412c749 ("mips: Add MT halting and waking of VPEs")
> Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org>
Confirmed with uarch behaviour.
Reviewed-by: Jiaxun Yang <jiaxun.y...@flygoat.com>
Thanks
Jiaxun
> ---
> Supersedes: <20210427103555.112652-1-f4...@amsat.org>
> v2: Check VPEConf0.MVP bit (hansni)
> ---
> target/mips/cp0_helper.c | 32 ++++++++++++++++++--------------
> 1 file changed, 18 insertions(+), 14 deletions(-)
>
> diff --git a/target/mips/cp0_helper.c b/target/mips/cp0_helper.c
> index aae2af6eccc..d5f274f5cdf 100644
> --- a/target/mips/cp0_helper.c
> +++ b/target/mips/cp0_helper.c
> @@ -1635,12 +1635,14 @@ target_ulong helper_dvpe(CPUMIPSState *env)
> CPUState *other_cs = first_cpu;
> target_ulong prev = env->mvp->CP0_MVPControl;
>
> - CPU_FOREACH(other_cs) {
> - MIPSCPU *other_cpu = MIPS_CPU(other_cs);
> - /* Turn off all VPEs except the one executing the dvpe. */
> - if (&other_cpu->env != env) {
> - other_cpu->env.mvp->CP0_MVPControl &= ~(1 << CP0MVPCo_EVP);
> - mips_vpe_sleep(other_cpu);
> + if (env->CP0_VPEConf0 & (1 << CP0VPEC0_MVP)) {
> + CPU_FOREACH(other_cs) {
> + MIPSCPU *other_cpu = MIPS_CPU(other_cs);
> + /* Turn off all VPEs except the one executing the dvpe. */
> + if (&other_cpu->env != env) {
> + other_cpu->env.mvp->CP0_MVPControl &= ~(1 << CP0MVPCo_EVP);
> + mips_vpe_sleep(other_cpu);
> + }
> }
> }
> return prev;
> @@ -1651,15 +1653,17 @@ target_ulong helper_evpe(CPUMIPSState *env)
> CPUState *other_cs = first_cpu;
> target_ulong prev = env->mvp->CP0_MVPControl;
>
> - CPU_FOREACH(other_cs) {
> - MIPSCPU *other_cpu = MIPS_CPU(other_cs);
> + if (env->CP0_VPEConf0 & (1 << CP0VPEC0_MVP)) {
> + CPU_FOREACH(other_cs) {
> + MIPSCPU *other_cpu = MIPS_CPU(other_cs);
>
> - if (&other_cpu->env != env
> - /* If the VPE is WFI, don't disturb its sleep. */
> - && !mips_vpe_is_wfi(other_cpu)) {
> - /* Enable the VPE. */
> - other_cpu->env.mvp->CP0_MVPControl |= (1 << CP0MVPCo_EVP);
> - mips_vpe_wake(other_cpu); /* And wake it up. */
> + if (&other_cpu->env != env
> + /* If the VPE is WFI, don't disturb its sleep. */
> + && !mips_vpe_is_wfi(other_cpu)) {
> + /* Enable the VPE. */
> + other_cpu->env.mvp->CP0_MVPControl |= (1 << CP0MVPCo_EVP);
> + mips_vpe_wake(other_cpu); /* And wake it up. */
> + }
> }
> }
> return prev;
> --
> 2.26.3
--
- Jiaxun
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1926277
Title:
MIPS MT dvpe does not regard VPEConf0.MVP
Status in QEMU:
Invalid
Bug description:
Hi,
According to MIPS32® Architecture for Programmers VolumeIV-f: The
MIPS® MT Application-Specific Extension to the MIPS32® Architecture,
for instruction: dvpe, evpe:
If the VPE executing the instruction is not a Master VPE, with the MVP
bit of the VPEConf0 register set, the EVP bit is unchanged by the
instruction.
The pseudo code is:
data ← MVPControl
GPR[rt] ← data
if(VPEConf0.MVP = 1) then
MVPControl.EVP ← sc
endif
However the helper functions of dvpe, evpe does not regard the
VPEConf0.MVP bit, namely, it does not check if the VPE is a master
VPE. Code is copied below as:
target_ulong helper_dvpe(CPUMIPSState *env)
{
CPUState *other_cs = first_cpu;
target_ulong prev = env->mvp->CP0_MVPControl;
CPU_FOREACH(other_cs) {
MIPSCPU *other_cpu = MIPS_CPU(other_cs);
/* Turn off all VPEs except the one executing the dvpe. */
if (&other_cpu->env != env) {
other_cpu->env.mvp->CP0_MVPControl &= ~(1 << CP0MVPCo_EVP);
mips_vpe_sleep(other_cpu);
}
}
return prev;
}
Is this a bug?
QEMU head commit: 0cef06d18762374c94eb4d511717a4735d668a24 is checked.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1926277/+subscriptions
