From: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
To: maobibo <maobibo@loongson.cn>,
pbonzini@redhat.com, tsbogend@alpha.franken.de,
paulus@ozlabs.org, mpe@ellerman.id.au, benh@kernel.crashing.org,
borntraeger@de.ibm.com, frankja@linux.ibm.com, david@redhat.com,
cohuck@redhat.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com,
sean.j.christopherson@intel.com, vkuznets@redhat.com,
wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
x86@kernel.org, hpa@zytor.com, maz@kernel.org,
james.morse@arm.com, julien.thierry.kdev@gmail.com,
suzuki.poulose@arm.com, christoffer.dall@arm.com,
peterx@redhat.com, thuth@redhat.com
Cc: linux-s390@vger.kernel.org, kvm@vger.kernel.org,
linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 7/7] KVM: MIPS: clean up redundant kvm_run parameters in assembly
Date: Mon, 20 Apr 2020 18:42:15 +0800 [thread overview]
Message-ID: <793b2b58-a199-c067-aec7-b07c444a6091@linux.alibaba.com> (raw)
In-Reply-To: <0b110e7f-9d08-496e-158e-8c3ff7307423@loongson.cn>
On 2020/4/20 18:32, maobibo wrote:
>
>
> On 04/19/2020 03:51 PM, Tianjia Zhang wrote:
>> In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
>> structure. Earlier than historical reasons, many kvm-related function
>> parameters retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time.
>> This patch does a unified cleanup of these remaining redundant parameters.
>>
>> Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
>> ---
>> arch/mips/include/asm/kvm_host.h | 4 ++--
>> arch/mips/kvm/entry.c | 15 +++++----------
>> arch/mips/kvm/mips.c | 3 ++-
>> arch/mips/kvm/trap_emul.c | 2 +-
>> arch/mips/kvm/vz.c | 2 +-
>> 5 files changed, 11 insertions(+), 15 deletions(-)
>>
>> diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
>> index 971439297cea..db915c55166d 100644
>> --- a/arch/mips/include/asm/kvm_host.h
>> +++ b/arch/mips/include/asm/kvm_host.h
>> @@ -310,7 +310,7 @@ struct kvm_mmu_memory_cache {
>> #define KVM_MIPS_GUEST_TLB_SIZE 64
>> struct kvm_vcpu_arch {
>> void *guest_ebase;
>> - int (*vcpu_run)(struct kvm_run *run, struct kvm_vcpu *vcpu);
>> + int (*vcpu_run)(struct kvm_vcpu *vcpu);
>>
>> /* Host registers preserved across guest mode execution */
>> unsigned long host_stack;
>> @@ -821,7 +821,7 @@ int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks);
>> /* Debug: dump vcpu state */
>> int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);
>>
>> -extern int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu);
>> +extern int kvm_mips_handle_exit(struct kvm_vcpu *vcpu);
>>
>> /* Building of entry/exception code */
>> int kvm_mips_entry_setup(void);
>> diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c
>> index 16e1c93b484f..e3f29af3b6cd 100644
>> --- a/arch/mips/kvm/entry.c
>> +++ b/arch/mips/kvm/entry.c
>> @@ -204,7 +204,7 @@ static inline void build_set_exc_base(u32 **p, unsigned int reg)
>> * Assemble the start of the vcpu_run function to run a guest VCPU. The function
>> * conforms to the following prototype:
>> *
>> - * int vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu);
>> + * int vcpu_run(struct kvm_vcpu *vcpu);
>> *
>> * The exit from the guest and return to the caller is handled by the code
>> * generated by kvm_mips_build_ret_to_host().
>> @@ -217,8 +217,7 @@ void *kvm_mips_build_vcpu_run(void *addr)
>> unsigned int i;
>>
>> /*
>> - * A0: run
>> - * A1: vcpu
>> + * A0: vcpu
>> */
>>
>> /* k0/k1 not being used in host kernel context */
>> @@ -237,10 +236,10 @@ void *kvm_mips_build_vcpu_run(void *addr)
>> kvm_mips_build_save_scratch(&p, V1, K1);
>>
>> /* VCPU scratch register has pointer to vcpu */
>> - UASM_i_MTC0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]);
>> + UASM_i_MTC0(&p, A0, scratch_vcpu[0], scratch_vcpu[1]);
>>
>> /* Offset into vcpu->arch */
>> - UASM_i_ADDIU(&p, K1, A1, offsetof(struct kvm_vcpu, arch));
>> + UASM_i_ADDIU(&p, K1, A0, offsetof(struct kvm_vcpu, arch));
>>
>> /*
>> * Save the host stack to VCPU, used for exception processing
>> @@ -628,10 +627,7 @@ void *kvm_mips_build_exit(void *addr)
>> /* Now that context has been saved, we can use other registers */
>>
>> /* Restore vcpu */
>> - UASM_i_MFC0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]);
>> -
>> - /* Restore run (vcpu->run) */
>> - UASM_i_LW(&p, S0, offsetof(struct kvm_vcpu, run), S1);
>> + UASM_i_MFC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);
>>
>> /*
>> * Save Host level EPC, BadVaddr and Cause to VCPU, useful to process
>> @@ -793,7 +789,6 @@ void *kvm_mips_build_exit(void *addr)
>> * with this in the kernel
>> */
>> uasm_i_move(&p, A0, S0);
>> - uasm_i_move(&p, A1, S1);
>> UASM_i_LA(&p, T9, (unsigned long)kvm_mips_handle_exit);
>> uasm_i_jalr(&p, RA, T9);
>> UASM_i_ADDIU(&p, SP, SP, -CALLFRAME_SIZ);
>
> I suggest keeping asm code untouched, the change for c code is much easier to understand, however I do not see obvious advantage to remove one redundant function parameter :)
>
>
> regards
> bibo,mao
>
This is acceptable, asm code is an independent patch, is to provide
convenience for this operation.
>
>> diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
>> index 9710477a9827..32850470c037 100644
>> --- a/arch/mips/kvm/mips.c
>> +++ b/arch/mips/kvm/mips.c
>> @@ -1186,8 +1186,9 @@ static void kvm_mips_set_c0_status(void)
>> /*
>> * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
>> */
>> -int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
>> +int kvm_mips_handle_exit(struct kvm_vcpu *vcpu)
>> {
>> + struct kvm_run *run = vcpu->run;
>> u32 cause = vcpu->arch.host_cp0_cause;
>> u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
>> u32 __user *opc = (u32 __user *) vcpu->arch.pc;
>> diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
>> index d822f3aee3dc..04c864cc356a 100644
>> --- a/arch/mips/kvm/trap_emul.c
>> +++ b/arch/mips/kvm/trap_emul.c
>> @@ -1238,7 +1238,7 @@ static int kvm_trap_emul_vcpu_run(struct kvm_vcpu *vcpu)
>> */
>> kvm_mips_suspend_mm(cpu);
>>
>> - r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
>> + r = vcpu->arch.vcpu_run(vcpu);
>>
>> /* We may have migrated while handling guest exits */
>> cpu = smp_processor_id();
>> diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
>> index 94f1d23828e3..c5878fa0636d 100644
>> --- a/arch/mips/kvm/vz.c
>> +++ b/arch/mips/kvm/vz.c
>> @@ -3152,7 +3152,7 @@ static int kvm_vz_vcpu_run(struct kvm_vcpu *vcpu)
>> kvm_vz_vcpu_load_tlb(vcpu, cpu);
>> kvm_vz_vcpu_load_wired(vcpu);
>>
>> - r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
>> + r = vcpu->arch.vcpu_run(vcpu);
>>
>> kvm_vz_vcpu_save_wired(vcpu);
>>
>>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
prev parent reply other threads:[~2020-04-20 10:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-19 7:50 [PATCH 0/7] clean up redundant 'kvm_run' parameters Tianjia Zhang
2020-04-19 7:51 ` [PATCH 1/7] KVM: s390: " Tianjia Zhang
2020-04-20 7:07 ` Christian Borntraeger
2020-04-20 7:17 ` Tianjia Zhang
2020-04-20 8:25 ` Janosch Frank
2020-04-19 7:51 ` [PATCH 2/7] KVM: arm64: " Tianjia Zhang
2020-04-19 7:51 ` [PATCH 3/7] KVM: PPC: Remove redundant kvm_run from vcpu_arch Tianjia Zhang
2020-04-19 7:51 ` [PATCH 4/7] KVM: PPC: clean up redundant 'kvm_run' parameters Tianjia Zhang
2020-04-19 7:51 ` [PATCH 5/7] KVM: PPC: clean up redundant kvm_run parameters in assembly Tianjia Zhang
2020-04-19 7:51 ` [PATCH 6/7] KVM: MIPS: clean up redundant 'kvm_run' parameters Tianjia Zhang
2020-04-19 7:51 ` [PATCH 7/7] KVM: MIPS: clean up redundant kvm_run parameters in assembly Tianjia Zhang
2020-04-20 10:32 ` maobibo
2020-04-20 10:42 ` Tianjia Zhang [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=793b2b58-a199-c067-aec7-b07c444a6091@linux.alibaba.com \
--to=tianjia.zhang@linux.alibaba.com \
--cc=benh@kernel.crashing.org \
--cc=borntraeger@de.ibm.com \
--cc=bp@alien8.de \
--cc=christoffer.dall@arm.com \
--cc=cohuck@redhat.com \
--cc=david@redhat.com \
--cc=frankja@linux.ibm.com \
--cc=gor@linux.ibm.com \
--cc=heiko.carstens@de.ibm.com \
--cc=hpa@zytor.com \
--cc=james.morse@arm.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=julien.thierry.kdev@gmail.com \
--cc=kvm-ppc@vger.kernel.org \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=maobibo@loongson.cn \
--cc=maz@kernel.org \
--cc=mingo@redhat.com \
--cc=mpe@ellerman.id.au \
--cc=paulus@ozlabs.org \
--cc=pbonzini@redhat.com \
--cc=peterx@redhat.com \
--cc=sean.j.christopherson@intel.com \
--cc=suzuki.poulose@arm.com \
--cc=tglx@linutronix.de \
--cc=thuth@redhat.com \
--cc=tsbogend@alpha.franken.de \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).