Re: [PATCH v2 06/58] i386/tdx: Get tdx_capabilities via KVM_TDX_CAPABILITIES

["Daniel P. Berrangé" <berrange@redhat.com>]

On Tue, Aug 22, 2023 at 03:31:44PM +0800, Xiaoyao Li wrote:
> On 8/21/2023 4:46 PM, Daniel P. Berrangé wrote:
> > On Fri, Aug 18, 2023 at 05:49:49AM -0400, Xiaoyao Li wrote:
> > > KVM provides TDX capabilities via sub command KVM_TDX_CAPABILITIES of
> > > IOCTL(KVM_MEMORY_ENCRYPT_OP). Get the capabilities when initializing
> > > TDX context. It will be used to validate user's setting later.
> > > 
> > > Since there is no interface reporting how many cpuid configs contains in
> > > KVM_TDX_CAPABILITIES, QEMU chooses to try starting with a known number
> > > and abort when it exceeds KVM_MAX_CPUID_ENTRIES.
> > > 
> > > Besides, introduce the interfaces to invoke TDX "ioctls" at different
> > > scope (KVM, VM and VCPU) in preparation.
> > > 
> > > Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
> > > ---
> > > changes from v1:
> > >    - Make the error message more clear;
> > > 
> > > changes from RFC v4:
> > >    - start from nr_cpuid_configs = 6 for the loop;
> > >    - stop the loop when nr_cpuid_configs exceeds KVM_MAX_CPUID_ENTRIES;
> > > ---
> > >   target/i386/kvm/kvm.c      |  2 -
> > >   target/i386/kvm/kvm_i386.h |  2 +
> > >   target/i386/kvm/tdx.c      | 93 ++++++++++++++++++++++++++++++++++++++
> > >   3 files changed, 95 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
> > > index d6b988d6c2d1..ec5c07bffd38 100644
> > > --- a/target/i386/kvm/kvm.c
> > > +++ b/target/i386/kvm/kvm.c
> > > @@ -1751,8 +1751,6 @@ static int hyperv_init_vcpu(X86CPU *cpu)
> > >   static Error *invtsc_mig_blocker;
> > > -#define KVM_MAX_CPUID_ENTRIES  100
> > > -
> > >   static void kvm_init_xsave(CPUX86State *env)
> > >   {
> > >       if (has_xsave2) {
> > > diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h
> > > index ea3a5b174ac0..769eadbba56c 100644
> > > --- a/target/i386/kvm/kvm_i386.h
> > > +++ b/target/i386/kvm/kvm_i386.h
> > > @@ -13,6 +13,8 @@
> > >   #include "sysemu/kvm.h"
> > > +#define KVM_MAX_CPUID_ENTRIES  100
> > > +
> > >   #define kvm_apic_in_kernel() (kvm_irqchip_in_kernel())
> > >   #ifdef CONFIG_KVM
> > > diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
> > > index 77e33ae01147..255c47a2a553 100644
> > > --- a/target/i386/kvm/tdx.c
> > > +++ b/target/i386/kvm/tdx.c
> > > @@ -12,14 +12,107 @@
> > >    */
> > >   #include "qemu/osdep.h"
> > > +#include "qemu/error-report.h"
> > >   #include "qapi/error.h"
> > >   #include "qom/object_interfaces.h"
> > > +#include "sysemu/kvm.h"
> > >   #include "hw/i386/x86.h"
> > > +#include "kvm_i386.h"
> > >   #include "tdx.h"
> > > +static struct kvm_tdx_capabilities *tdx_caps;
> > > +
> > > +enum tdx_ioctl_level{
> > > +    TDX_PLATFORM_IOCTL,
> > > +    TDX_VM_IOCTL,
> > > +    TDX_VCPU_IOCTL,
> > > +};
> > > +
> > > +static int __tdx_ioctl(void *state, enum tdx_ioctl_level level, int cmd_id,
> > > +                        __u32 flags, void *data)
> > 
> > Names with an initial double underscore are reserved for us by the
> > platform implementation, so shouldn't be used in userspace app
> > code.
> 
> How about tdx_ioctl_internal() ?

Sure, that's fine.

With regards,
Daniel
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