On Wed, 2023-03-29 at 09:27 +0800, Binbin Wu wrote:
> On 3/29/2023 7:33 AM, Huang, Kai wrote:
> > On Tue, 2023-03-21 at 14:35 -0700, Sean Christopherson wrote:
> > > On Mon, Mar 20, 2023, Chao Gao wrote:
> > > > On Sun, Mar 19, 2023 at 04:49:22PM +0800, Binbin Wu wrote:
> > > > > get_vmx_mem_address() and sgx_get_encls_gva() use is_long_mode()
> > > > > to check 64-bit mode. Should use is_64_bit_mode() instead.
> > > > >
> > > > > Fixes: f9eb4af67c9d ("KVM: nVMX: VMX instructions: add checks for #GP/#SS exceptions")
> > > > > Fixes: 70210c044b4e ("KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions")
> > > > It is better to split this patch into two: one for nested and one for
> > > > SGX.
> > > >
> > > > It is possible that there is a kernel release which has just one of
> > > > above two flawed commits, then this fix patch cannot be applied cleanly
> > > > to the release.
> > > The nVMX code isn't buggy, VMX instructions #UD in compatibility mode, and except
> > > for VMCALL, that #UD has higher priority than VM-Exit interception. So I'd say
> > > just drop the nVMX side of things.
> > But it looks the old code doesn't unconditionally inject #UD when in
> > compatibility mode?
>
> I think Sean means VMX instructions is not valid in compatibility mode
> and it triggers #UD, which has higher priority than VM-Exit, by the
> processor in non-root mode.
>
> So if there is a VM-Exit due to VMX instruction , it is in 64-bit mode
> for sure if it is in long mode.
Oh I see thanks.
Then is it better to add some comment to explain, or add a WARN() if it's not in
64-bit mode?
