Re: [Xen-devel] [PATCH 1/3] vvmx: set vmxon_region_pa of vcpu out of VMX operation to an invalid address

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Tue, Dec 13, 2016 at 02:35:33PM +0000, Andrew Cooper wrote:
> On 13/12/16 12:16, Haozhong Zhang wrote:
> > nvmx_handle_vmxon() previously checks whether a vcpu is in VMX
> > operation by comparing its vmxon_region_pa with GPA 0. However, 0 is
> > also a valid VMXON region address. If L1 hypervisor had set the VMXON
> > region address to 0, the check in nvmx_handle_vmxon() will be skipped.
> > Fix this problem by using an invalid VMXON region address for vcpu
> > out of VMX operation.
> >
> > Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
> > ---
> >  xen/arch/x86/hvm/vmx/vvmx.c | 20 ++++++++++++++++----
> >  1 file changed, 16 insertions(+), 4 deletions(-)
> >
> > diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
> > index e6e9ebd..f5637eb 100644
> > --- a/xen/arch/x86/hvm/vmx/vvmx.c
> > +++ b/xen/arch/x86/hvm/vmx/vvmx.c
> > @@ -32,6 +32,18 @@ static DEFINE_PER_CPU(u64 *, vvmcs_buf);
> >  
> >  static void nvmx_purge_vvmcs(struct vcpu *v);
> >  
> > +/*
> > + * When a vcpu is out of VMXON region, set its vmxon_region_pa to
> > + * INVALID_VMXON_REGION_PA. We cannot use 0, because 0 is also a valid
> > + * VMXON region address.
> > + */
> > +#define INVALID_VMXON_REGION_PA (~0UL)
> > +
> > +static bool nvmx_vcpu_in_vmx(struct vcpu *v)
> 
> const struct vcpu *v.
> 
> Otherwise, Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

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