Re: [PATCH V6 1/4] hw/mips: Implement the kvm_type() hook in MachineClass

From: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
To: Huacai Chen <zltjiangshi@gmail.com>
Cc: "Aleksandar Rikalo" <aleksandar.rikalo@syrmia.com>,
	"Huacai Chen" <chenhuacai@gmail.com>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>,
	"QEMU Developers" <qemu-devel@nongnu.org>,
	"Huacai Chen" <chenhc@lemote.com>,
	"Aurelien Jarno" <aurelien@aurel32.net>
Subject: Re: [PATCH V6 1/4] hw/mips: Implement the kvm_type() hook in MachineClass
Date: Thu, 25 Jun 2020 14:31:01 +0200	[thread overview]
Message-ID: <CAHiYmc5ZbZSyMxevp-Ta1fWsY67yt6S_bhoHr5CGYPWN=KTLbQ@mail.gmail.com> (raw)
In-Reply-To: <1592995531-32600-2-git-send-email-chenhc@lemote.com>

сре, 24. јун 2020. у 12:44 Huacai Chen <zltjiangshi@gmail.com> је написао/ла:
>
> MIPS has two types of KVM: TE & VZ, and TE is the default type. Now we
> can't create a VZ guest in QEMU because it lacks the kvm_type() hook in
> MachineClass. This patch add the the kvm_type() hook to support both of
> the two types.
>
> Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
> Signed-off-by: Huacai Chen <chenhc@lemote.com>
> Co-developed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  target/mips/kvm.c      | 20 ++++++++++++++++++++
>  target/mips/kvm_mips.h | 11 +++++++++++
>  2 files changed, 31 insertions(+)
>
> diff --git a/target/mips/kvm.c b/target/mips/kvm.c
> index 96cfa10..373f582 100644
> --- a/target/mips/kvm.c
> +++ b/target/mips/kvm.c
> @@ -21,10 +21,12 @@
>  #include "qemu/main-loop.h"
>  #include "qemu/timer.h"
>  #include "sysemu/kvm.h"
> +#include "sysemu/kvm_int.h"
>  #include "sysemu/runstate.h"
>  #include "sysemu/cpus.h"
>  #include "kvm_mips.h"
>  #include "exec/memattrs.h"
> +#include "hw/boards.h"
>
>  #define DEBUG_KVM 0
>
> @@ -1270,3 +1272,21 @@ int kvm_arch_msi_data_to_gsi(uint32_t data)
>  {
>      abort();
>  }
> +
> +int mips_kvm_type(MachineState *machine, const char *vm_type)
> +{
> +    int r;
> +    KVMState *s = KVM_STATE(machine->accelerator);
> +
> +    r = kvm_check_extension(s, KVM_CAP_MIPS_VZ);

This will not work for build systems with kernel < 4.12. You need to
provide fallback solution for that case.

> +    if (r > 0) {
> +        return KVM_VM_MIPS_VZ;
> +    }
> +
> +    r = kvm_check_extension(s, KVM_CAP_MIPS_TE);
> +    if (r > 0) {
> +        return KVM_VM_MIPS_TE;
> +    }
> +
> +    return -1;
> +}
> diff --git a/target/mips/kvm_mips.h b/target/mips/kvm_mips.h
> index 1e40147..171d53d 100644
> --- a/target/mips/kvm_mips.h
> +++ b/target/mips/kvm_mips.h
> @@ -12,6 +12,8 @@
>  #ifndef KVM_MIPS_H
>  #define KVM_MIPS_H
>
> +#include "cpu.h"
> +
>  /**
>   * kvm_mips_reset_vcpu:
>   * @cpu: MIPSCPU
> @@ -23,4 +25,13 @@ void kvm_mips_reset_vcpu(MIPSCPU *cpu);
>  int kvm_mips_set_interrupt(MIPSCPU *cpu, int irq, int level);
>  int kvm_mips_set_ipi_interrupt(MIPSCPU *cpu, int irq, int level);
>
> +#ifdef CONFIG_KVM
> +int mips_kvm_type(MachineState *machine, const char *vm_type);
> +#else
> +static inline int mips_kvm_type(MachineState *machine, const char *vm_type)
> +{
> +    return 0;
> +}
> +#endif
> +
>  #endif /* KVM_MIPS_H */
> --
> 2.7.0
>