Re: [kvm-unit-tests PATCH 15/16] svm: introduce svm_vcpu

[Sean Christopherson <seanjc@google.com>]

On Thu, Oct 20, 2022, Maxim Levitsky wrote:
> This adds minimum amout of code to support tests that
> run SVM on more that one vCPU.

s/that/than

> 
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---
>  lib/x86/svm_lib.c |   9 +
>  lib/x86/svm_lib.h |  10 +
>  x86/svm.c         |  37 ++-
>  x86/svm.h         |   5 +-
>  x86/svm_npt.c     |  44 ++--
>  x86/svm_tests.c   | 615 +++++++++++++++++++++++-----------------------
>  6 files changed, 362 insertions(+), 358 deletions(-)
> 
> diff --git a/lib/x86/svm_lib.c b/lib/x86/svm_lib.c
> index 2b067c65..1152c497 100644
> --- a/lib/x86/svm_lib.c
> +++ b/lib/x86/svm_lib.c
> @@ -157,3 +157,12 @@ void vmcb_ident(struct vmcb *vmcb)
>  		ctrl->tlb_ctl = TLB_CONTROL_FLUSH_ALL_ASID;
>  	}
>  }
> +
> +void svm_vcpu_init(struct svm_vcpu *vcpu)
> +{
> +	vcpu->vmcb = alloc_page();
> +	vmcb_ident(vcpu->vmcb);
> +	memset(&vcpu->regs, 0, sizeof(vcpu->regs));
> +	vcpu->stack = alloc_pages(4) + (PAGE_SIZE << 4);
> +	vcpu->vmcb->save.rsp = (ulong)(vcpu->stack);
> +}
> diff --git a/lib/x86/svm_lib.h b/lib/x86/svm_lib.h
> index 59db26de..c6957dba 100644
> --- a/lib/x86/svm_lib.h
> +++ b/lib/x86/svm_lib.h
> @@ -89,6 +89,16 @@ struct svm_extra_regs
>      u64 r15;
>  };
>  
> +
> +struct svm_vcpu
> +{
> +	struct vmcb *vmcb;
> +	struct svm_extra_regs regs;
> +	void *stack;
> +};
> +
> +void svm_vcpu_init(struct svm_vcpu *vcpu);
> +
>  #define SWAP_GPRS(reg) \
>  		"xchg %%rcx, 0x08(%%" reg ")\n\t"       \
>  		"xchg %%rdx, 0x10(%%" reg ")\n\t"       \
> diff --git a/x86/svm.c b/x86/svm.c
> index 9484a6d1..7aa3ebd2 100644
> --- a/x86/svm.c
> +++ b/x86/svm.c
> @@ -16,7 +16,7 @@
>  #include "apic.h"
>  #include "svm_lib.h"
>  
> -struct vmcb *vmcb;
> +struct svm_vcpu vcpu0;

It's not strictly vCPU0, e.g. svm_init_intercept_test() deliberately runs on
vCPU2, presumably to avoid running on the BSP?

Since this is churning a lot of code anyways, why not clean this all up and have
run_svm_tests() dynamically allocate state instead of relying on global data?