From: maobibo <maobibo@loongson.cn>
To: Huacai Chen <chenhuacai@kernel.org>
Cc: Tianrui Zhao <zhaotianrui@loongson.cn>,
Juergen Gross <jgross@suse.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Jonathan Corbet <corbet@lwn.net>,
loongarch@lists.linux.dev, linux-kernel@vger.kernel.org,
virtualization@lists.linux.dev, kvm@vger.kernel.org
Subject: Re: [PATCH v8 2/6] LoongArch: KVM: Add hypercall instruction emulation support
Date: Mon, 6 May 2024 10:41:02 +0800 [thread overview]
Message-ID: <dab88e08-5d56-3a65-df35-47842111a8dc@loongson.cn> (raw)
In-Reply-To: <CAAhV-H5xVP0+aUyq2+_XHW0=25zxuG53o=+vUV4MfKn=4tiwxA@mail.gmail.com>
On 2024/5/6 上午9:54, Huacai Chen wrote:
> Hi, Bibo,
>
> On Sun, Apr 28, 2024 at 6:05 PM Bibo Mao <maobibo@loongson.cn> wrote:
>>
>> On LoongArch system, there is hypercall instruction special for
>> virtualization. When system executes this instruction on host side,
>> there is illegal instruction exception reported, however it will
>> trap into host when it is executed in VM mode.
>>
>> When hypercall is emulated, A0 register is set with value
>> KVM_HCALL_INVALID_CODE, rather than inject EXCCODE_INE invalid
>> instruction exception. So VM can continue to executing the next code.
>>
>> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
>> ---
>> arch/loongarch/include/asm/Kbuild | 1 -
>> arch/loongarch/include/asm/kvm_para.h | 26 ++++++++++++++++++++++++++
>> arch/loongarch/include/uapi/asm/Kbuild | 2 --
>> arch/loongarch/kvm/exit.c | 10 ++++++++++
>> 4 files changed, 36 insertions(+), 3 deletions(-)
>> create mode 100644 arch/loongarch/include/asm/kvm_para.h
>> delete mode 100644 arch/loongarch/include/uapi/asm/Kbuild
>>
>> diff --git a/arch/loongarch/include/asm/Kbuild b/arch/loongarch/include/asm/Kbuild
>> index 2dbec7853ae8..c862672ed953 100644
>> --- a/arch/loongarch/include/asm/Kbuild
>> +++ b/arch/loongarch/include/asm/Kbuild
>> @@ -26,4 +26,3 @@ generic-y += poll.h
>> generic-y += param.h
>> generic-y += posix_types.h
>> generic-y += resource.h
>> -generic-y += kvm_para.h
>> diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h
>> new file mode 100644
>> index 000000000000..d48f993ae206
>> --- /dev/null
>> +++ b/arch/loongarch/include/asm/kvm_para.h
>> @@ -0,0 +1,26 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef _ASM_LOONGARCH_KVM_PARA_H
>> +#define _ASM_LOONGARCH_KVM_PARA_H
>> +
>> +/*
>> + * LoongArch hypercall return code
>> + */
>> +#define KVM_HCALL_STATUS_SUCCESS 0
>> +#define KVM_HCALL_INVALID_CODE -1UL
>> +#define KVM_HCALL_INVALID_PARAMETER -2UL
>> +
>> +static inline unsigned int kvm_arch_para_features(void)
>> +{
>> + return 0;
>> +}
>> +
>> +static inline unsigned int kvm_arch_para_hints(void)
>> +{
>> + return 0;
>> +}
>> +
>> +static inline bool kvm_check_and_clear_guest_paused(void)
>> +{
>> + return false;
>> +}
>> +#endif /* _ASM_LOONGARCH_KVM_PARA_H */
>> diff --git a/arch/loongarch/include/uapi/asm/Kbuild b/arch/loongarch/include/uapi/asm/Kbuild
>> deleted file mode 100644
>> index 4aa680ca2e5f..000000000000
>> --- a/arch/loongarch/include/uapi/asm/Kbuild
>> +++ /dev/null
>> @@ -1,2 +0,0 @@
>> -# SPDX-License-Identifier: GPL-2.0
>> -generic-y += kvm_para.h
> This file shouldn't be removed.
yes, uapi kvm_param.h is needed for Loongarch, and there will be problem
if it is removed. And it should kept unchanged.
Regards
Bibo Mao
>
> Huacai
>
>> diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
>> index ed1d89d53e2e..923bbca9bd22 100644
>> --- a/arch/loongarch/kvm/exit.c
>> +++ b/arch/loongarch/kvm/exit.c
>> @@ -685,6 +685,15 @@ static int kvm_handle_lasx_disabled(struct kvm_vcpu *vcpu)
>> return RESUME_GUEST;
>> }
>>
>> +static int kvm_handle_hypercall(struct kvm_vcpu *vcpu)
>> +{
>> + update_pc(&vcpu->arch);
>> +
>> + /* Treat it as noop intruction, only set return value */
>> + vcpu->arch.gprs[LOONGARCH_GPR_A0] = KVM_HCALL_INVALID_CODE;
>> + return RESUME_GUEST;
>> +}
>> +
>> /*
>> * LoongArch KVM callback handling for unimplemented guest exiting
>> */
>> @@ -716,6 +725,7 @@ static exit_handle_fn kvm_fault_tables[EXCCODE_INT_START] = {
>> [EXCCODE_LSXDIS] = kvm_handle_lsx_disabled,
>> [EXCCODE_LASXDIS] = kvm_handle_lasx_disabled,
>> [EXCCODE_GSPR] = kvm_handle_gspr,
>> + [EXCCODE_HVC] = kvm_handle_hypercall,
>> };
>>
>> int kvm_handle_fault(struct kvm_vcpu *vcpu, int fault)
>> --
>> 2.39.3
>>
>>
next prev parent reply other threads:[~2024-05-06 2:41 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-28 10:05 [PATCH v8 0/6] LoongArch: Add pv ipi support on LoongArch VM Bibo Mao
2024-04-28 10:05 ` [PATCH v8 1/6] LoongArch/smp: Refine some ipi functions on LoongArch platform Bibo Mao
2024-04-28 10:05 ` [PATCH v8 2/6] LoongArch: KVM: Add hypercall instruction emulation support Bibo Mao
2024-05-06 1:54 ` Huacai Chen
2024-05-06 2:41 ` maobibo [this message]
2024-04-28 10:05 ` [PATCH v8 3/6] LoongArch: KVM: Add cpucfg area for kvm hypervisor Bibo Mao
2024-04-28 16:38 ` kernel test robot
2024-04-28 10:05 ` [PATCH v8 4/6] LoongArch: KVM: Add vcpu search support from physical cpuid Bibo Mao
2024-05-06 1:49 ` Huacai Chen
2024-05-06 2:29 ` maobibo
2024-05-06 6:36 ` maobibo
2024-05-06 7:06 ` Huacai Chen
2024-05-06 8:18 ` maobibo
2024-05-06 8:59 ` Huacai Chen
2024-05-06 9:35 ` maobibo
2024-05-06 9:40 ` Huacai Chen
2024-05-06 10:05 ` maobibo
2024-05-06 14:17 ` Huacai Chen
2024-05-07 1:40 ` maobibo
2024-05-07 2:05 ` Huacai Chen
2024-05-07 3:06 ` maobibo
2024-05-08 5:00 ` Huacai Chen
2024-05-08 6:10 ` maobibo
2024-04-28 10:05 ` [PATCH v8 5/6] LoongArch: KVM: Add pv ipi support on kvm side Bibo Mao
2024-04-28 10:05 ` [PATCH v8 6/6] LoongArch: Add pv ipi support on guest kernel side Bibo Mao
2024-05-06 1:53 ` Huacai Chen
2024-05-06 7:00 ` maobibo
2024-05-06 7:04 ` Huacai Chen
2024-05-06 1:45 ` [PATCH v8 0/6] LoongArch: Add pv ipi support on LoongArch VM Huacai Chen
2024-05-06 6:32 ` maobibo
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=dab88e08-5d56-3a65-df35-47842111a8dc@loongson.cn \
--to=maobibo@loongson.cn \
--cc=chenhuacai@kernel.org \
--cc=corbet@lwn.net \
--cc=jgross@suse.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=loongarch@lists.linux.dev \
--cc=pbonzini@redhat.com \
--cc=virtualization@lists.linux.dev \
--cc=zhaotianrui@loongson.cn \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).