Re: [PATCH] kvm-unit-tests: VMX: Fix confused definition of rflags

[Gleb Natapov <gleb@redhat.com>]

On Tue, Jul 30, 2013 at 11:41:00PM +0800, Arthur Chunqi Li wrote:
> Change "rflags" in "struct regs" to "host_rflags". Remove settings
> to GUEST_RFLAGS since GUEST_RFLAGS can be set by vmwrite. Treat
> host_rflags as host rflags before and after vmenter.
> 
I am not sure the change is for the better. Before the change one could
set up rflags for guest environment by setting regs.rflags, no special
init function had to be written. I do not see any problem with correct
code, except that rflags is not correct on a guest entry, but this
should be easy to fix. 

> Besides, add checks to flags after vmenter.
> 
> Signed-off-by: Arthur Chunqi Li <yzt356@gmail.com>
> ---
>  x86/vmx.c |   11 ++++++-----
>  x86/vmx.h |    2 +-
>  2 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/x86/vmx.c b/x86/vmx.c
> index 7467927..082c3bb 100644
> --- a/x86/vmx.c
> +++ b/x86/vmx.c
> @@ -481,6 +481,8 @@ static int vmx_run()
>  			"vmresume\n\t"
>  			"2: "
>  			"setbe %0\n\t"
> +			"jbe vmx_return\n\t"
> +			"ud2\n\t"
>  			"vmx_return:\n\t"
>  			SAVE_GPR_C
>  			SAVE_RFLAGS
> @@ -505,15 +507,15 @@ static int vmx_run()
>  		return 0;
>  	case VMX_TEST_LAUNCH_ERR:
>  		printf("%s : vmlaunch failed.\n", __func__);
> -		if ((!(regs.rflags & X86_EFLAGS_CF) && !(regs.rflags & X86_EFLAGS_ZF))
> -			|| ((regs.rflags & X86_EFLAGS_CF) && (regs.rflags & X86_EFLAGS_ZF)))
> +		if ((!(regs.host_rflags & X86_EFLAGS_CF) && !(regs.host_rflags & X86_EFLAGS_ZF))
> +			|| ((regs.host_rflags & X86_EFLAGS_CF) && (regs.host_rflags & X86_EFLAGS_ZF)))
>  			printf("\tvmlaunch set wrong flags\n");
>  		report("test vmlaunch", 0);
>  		break;
>  	case VMX_TEST_RESUME_ERR:
>  		printf("%s : vmresume failed.\n", __func__);
> -		if ((!(regs.rflags & X86_EFLAGS_CF) && !(regs.rflags & X86_EFLAGS_ZF))
> -			|| ((regs.rflags & X86_EFLAGS_CF) && (regs.rflags & X86_EFLAGS_ZF)))
> +		if ((!(regs.host_rflags & X86_EFLAGS_CF) && !(regs.host_rflags & X86_EFLAGS_ZF))
> +			|| ((regs.host_rflags & X86_EFLAGS_CF) && (regs.host_rflags & X86_EFLAGS_ZF)))
>  			printf("\tvmresume set wrong flags\n");
>  		report("test vmresume", 0);
>  		break;
> @@ -540,7 +542,6 @@ static int test_run(struct vmx_test *test)
>  	test->exits = 0;
>  	current = test;
>  	regs = test->guest_regs;
> -	vmcs_write(GUEST_RFLAGS, regs.rflags | 0x2);
>  	launched = 0;
>  	printf("\nTest suite : %s\n", test->name);
>  	vmx_run();
> diff --git a/x86/vmx.h b/x86/vmx.h
> index 1fb9738..d80e000 100644
> --- a/x86/vmx.h
> +++ b/x86/vmx.h
> @@ -27,7 +27,7 @@ struct regs {
>  	u64 r13;
>  	u64 r14;
>  	u64 r15;
> -	u64 rflags;
> +	u64 host_rflags;
>  };
>  
>  struct vmx_test {
> -- 
> 1.7.9.5

--
			Gleb.