On Tue, Jan 30, 2024 at 11:42:43AM +0100, Jan Beulich wrote:
> On 30.01.2024 11:27, Roger Pau Monne wrote:
> > Dummy set/clear tests for additional spec_ctrl bits.
> > ---
> > docs/all-tests.dox | 2 +
> > tests/test/Makefile | 9 ++++
> > tests/test/main.c | 100 ++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 111 insertions(+)
> > create mode 100644 tests/test/Makefile
> > create mode 100644 tests/test/main.c
>
> I'm puzzled: Why "test"? That doesn't describe in any way what this test
> is about.
That's just my place holder for random XTF stuff. I don't intend this
to be committed.
> > --- /dev/null
> > +++ b/tests/test/Makefile
> > @@ -0,0 +1,9 @@
> > +include $(ROOT)/build/common.mk
> > +
> > +NAME := test
> > +CATEGORY := utility
> > +TEST-ENVS := hvm32 pv64
>
> Any reason for this limitation?
Just wanted a PV and an HVM context.
> > --- /dev/null
> > +++ b/tests/test/main.c
> > @@ -0,0 +1,100 @@
> > +/**
> > + * @file tests/test/main.c
> > + * @ref test-test
> > + *
> > + * @page test-test test
> > + *
> > + * @todo Docs for test-test
> > + *
> > + * @see tests/test/main.c
> > + */
> > +#include <xtf.h>
> > +
> > +#define MSR_SPEC_CTRL 0x00000048
> > +#define SPEC_CTRL_IPRED_DIS_U (_AC(1, ULL) << 3)
> > +#define SPEC_CTRL_IPRED_DIS_S (_AC(1, ULL) << 4)
> > +#define SPEC_CTRL_RRSBA_DIS_U (_AC(1, ULL) << 5)
> > +#define SPEC_CTRL_RRSBA_DIS_S (_AC(1, ULL) << 6)
> > +#define SPEC_CTRL_DDP_DIS_U (_AC(1, ULL) << 8)
> > +#define SPEC_CTRL_BHI_DIS_S (_AC(1, ULL) << 10)
> > +
> > +const char test_title[] = "SPEC_CTRL";
> > +
> > +static void update_spec_ctrl(uint64_t mask, bool set)
> > +{
> > + uint64_t spec_ctrl = rdmsr(MSR_SPEC_CTRL);
> > +
> > + if ( set )
> > + spec_ctrl |= mask;
> > + else
> > + spec_ctrl &= ~mask;
> > +
> > + wrmsr(MSR_SPEC_CTRL, spec_ctrl);
> > +}
> > +
> > +static void assert_spec_ctrl(uint64_t mask, bool set)
> > +{
> > + uint64_t spec_ctrl = rdmsr(MSR_SPEC_CTRL);
> > +
> > + if ( (spec_ctrl & mask) != (set ? mask : 0) )
> > + {
> > + xtf_failure("SPEC_CTRL expected: %#" PRIx64 " got: %#" PRIx64 "\n",
> > + set ? (spec_ctrl | mask) : (spec_ctrl & ~mask),
> > + spec_ctrl);
> > + xtf_exit();
> > + }
> > +}
> > +
> > +static void test_loop(uint64_t mask)
> > +{
> > + update_spec_ctrl(mask, true);
> > + assert_spec_ctrl(mask, true);
> > + /* Ensure context switch to Xen. */
> > + hypercall_yield();
>
> I'm afraid yielding doesn't guarantee context switching in Xen,
It will ensure a vmexit/trap, which is what I was after here. Maybe the
comment should be "Trap into Xen." or some such. It wasn't about
ensuring VM context switching.
Thanks, Roger.
