On Tue, Sep 09, 2025 at 03:11:47AM +0000, Michael Kelley wrote: > From: Roman Kisel <[email protected]> Sent: Wednesday, August 27, > 2025 6:06 PM > > > > hv_set_non_nested_msr() has special handling for SINT MSRs > > when a paravisor is present. In addition to updating the MSR on the > > host, the mirror MSR in the paravisor is updated, including with the > > proxy bit. But with Confidential VMBus, the proxy bit must not be > > used, so add a special case to skip it. > > > > Signed-off-by: Roman Kisel <[email protected]> > > Reviewed-by: Alok Tiwari <[email protected]> > > Reviewed-by: Tianyu Lan <[email protected]> > > --- [...] > > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c > > index a619b661275b..5e2c6fd637d2 100644 > > --- a/arch/x86/kernel/cpu/mshyperv.c > > +++ b/arch/x86/kernel/cpu/mshyperv.c > > @@ -28,6 +28,7 @@ > > #include <asm/apic.h> > > #include <asm/timer.h> > > #include <asm/reboot.h> > > +#include <asm/msr.h> > > #include <asm/nmi.h> > > #include <clocksource/hyperv_timer.h> > > #include <asm/msr.h> > > @@ -38,6 +39,16 @@ > > bool hv_nested; > > struct ms_hyperv_info ms_hyperv; > > > > +#define HYPERV_SINT_PROXY_ENABLE BIT(20) > > +#define HYPERV_SINT_PROXY_DISABLE 0 > > Seems like these definitions belong in hvgdk_mini.h together with > the definition of "union hv_synic_sint". Since that union already > defines the "proxy" field, the definitions really should be in terms > of that field (though I'd have to fiddle with the code to figure out > if there's a reasonable way to do that). >
If we use sint.proxy (or sint->proxy) then we don't even need this definition. I think this is only needed because the code writes u64 directly to the MSR without reinterpreting it as hv_synic_sint. Wei
