| Message ID | 1422568135-28402-6-git-send-email-rkrcmar@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 29/01/2015 22:48, Radim Kr?má? wrote: > In mixed modes, we musn't deliver xAPIC IPIs like x2APIC and vice versa. > Instead of preserving the information in apic_send_ipi(), we regain it > by converting all destinations into correct APIC MDA in the slow path. > This allows easier reasoning about subsequent matching. > > kvm_apic_broadcast() had an interesting design decision: > it didn't consider IOxAPIC 0xff as broadcast in x2APIC mode ... > everything worked because IOxAPIC can't set that in physical mode and > logical mode considered it as a message for first 8 VCPUs. > This patch interprets IOxAPIC 0xff as x2APIC broadcast. > > Signed-off-by: Radim Kr?má? <rkrcmar@redhat.com> > --- > arch/x86/kvm/lapic.c | 40 +++++++++++++++++++++++++++++++++------- > 1 file changed, 33 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index aae043f38548..871ce6a2485b 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -581,15 +581,24 @@ static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr) > apic_update_ppr(apic); > } > > -static bool kvm_apic_broadcast(struct kvm_lapic *apic, u32 dest) > +static bool kvm_apic_broadcast(struct kvm_lapic *apic, u32 mda) > { > - return dest == (apic_x2apic_mode(apic) ? > - X2APIC_BROADCAST : APIC_BROADCAST); > + if (apic_x2apic_mode(apic)) > + return mda == X2APIC_BROADCAST; > + > + /* XXX: verify that xAPIC accepts x2APIC broadcast */ > + return GET_APIC_DEST_FIELD(mda) == APIC_BROADCAST; > } > > -static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 dest) > +static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda) > { > - return kvm_apic_id(apic) == dest || kvm_apic_broadcast(apic, dest); > + if (kvm_apic_broadcast(apic, mda)) > + return true; > + > + if (apic_x2apic_mode(apic)) > + return mda == kvm_apic_id(apic); > + > + return mda == SET_APIC_DEST_FIELD(kvm_apic_id(apic)); > } > > static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda) > @@ -606,6 +615,7 @@ static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda) > && (logical_id & mda & 0xffff); > > logical_id = GET_APIC_LOGICAL_ID(logical_id); > + mda = GET_APIC_DEST_FIELD(mda); > > switch (kvm_apic_get_reg(apic, APIC_DFR)) { > case APIC_DFR_FLAT: > @@ -620,10 +630,26 @@ static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda) > } > } > > +/* KVM APIC implementation has two quirks > + * - dest always begins at 0 while xAPIC MDA has offset 24, > + * - IOxAPIC messages have to be delivered (directly) to x2APIC. > + */ > +static u32 > +kvm_apic_mda(unsigned int dest, struct kvm_lapic *ipi, bool x2apic_dest) Please pass two struct kvm_lapic, so that you can write bool ipi = source != NULL; bool x2apic_mda = apic_x2apic_mode(ipi ? source : dest); Looks a little nicer to me at least. > +{ > + bool x2apic_mda = ipi ? apic_x2apic_mode(ipi) : x2apic_dest; > + > + if (!ipi && dest == APIC_BROADCAST) > + dest = X2APIC_BROADCAST; This works, but it is not super-clear that you are shifting left by 24 here, and right in kvm_apic_broadcast(). What if you just make it if (!ipi && dest == APIC_BROADCAST && x2apic_mda) return X2APIC_BROADCAST. ? Paolo > + > + return x2apic_mda ? dest : SET_APIC_DEST_FIELD(dest); > +} > + > bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source, > int short_hand, unsigned int dest, int dest_mode) > { > struct kvm_lapic *target = vcpu->arch.apic; > + u32 mda = kvm_apic_mda(dest, source, apic_x2apic_mode(target)); > > apic_debug("target %p, source %p, dest 0x%x, " > "dest_mode 0x%x, short_hand 0x%x\n", > @@ -633,9 +659,9 @@ bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source, > switch (short_hand) { > case APIC_DEST_NOSHORT: > if (dest_mode == APIC_DEST_PHYSICAL) > - return kvm_apic_match_physical_addr(target, dest); > + return kvm_apic_match_physical_addr(target, mda); > else > - return kvm_apic_match_logical_addr(target, dest); > + return kvm_apic_match_logical_addr(target, mda); > case APIC_DEST_SELF: > return target == source; > case APIC_DEST_ALLINC: > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2015-01-30 10:03+0100, Paolo Bonzini: > On 29/01/2015 22:48, Radim Kr?má? wrote: > > +/* KVM APIC implementation has two quirks > > + * - dest always begins at 0 while xAPIC MDA has offset 24, > > + * - IOxAPIC messages have to be delivered (directly) to x2APIC. > > + */ > > +static u32 > > +kvm_apic_mda(unsigned int dest, struct kvm_lapic *ipi, bool x2apic_dest) > > Please pass two struct kvm_lapic, so that you can write > > bool ipi = source != NULL; > bool x2apic_mda = apic_x2apic_mode(ipi ? source : dest); > > Looks a little nicer to me at least. Definitely. > > +{ > > + bool x2apic_mda = ipi ? apic_x2apic_mode(ipi) : x2apic_dest; > > + > > + if (!ipi && dest == APIC_BROADCAST) > > + dest = X2APIC_BROADCAST; > > This works, but it is not super-clear that you are shifting left by 24 > here, and right in kvm_apic_broadcast(). What if you just make it > > if (!ipi && dest == APIC_BROADCAST && x2apic_mda) > return X2APIC_BROADCAST. It's better, it will be that way in v2 of [5-8/8], thanks. (I was using it twice in earlier iterations and didn't think again.) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index aae043f38548..871ce6a2485b 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -581,15 +581,24 @@ static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr) apic_update_ppr(apic); } -static bool kvm_apic_broadcast(struct kvm_lapic *apic, u32 dest) +static bool kvm_apic_broadcast(struct kvm_lapic *apic, u32 mda) { - return dest == (apic_x2apic_mode(apic) ? - X2APIC_BROADCAST : APIC_BROADCAST); + if (apic_x2apic_mode(apic)) + return mda == X2APIC_BROADCAST; + + /* XXX: verify that xAPIC accepts x2APIC broadcast */ + return GET_APIC_DEST_FIELD(mda) == APIC_BROADCAST; } -static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 dest) +static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda) { - return kvm_apic_id(apic) == dest || kvm_apic_broadcast(apic, dest); + if (kvm_apic_broadcast(apic, mda)) + return true; + + if (apic_x2apic_mode(apic)) + return mda == kvm_apic_id(apic); + + return mda == SET_APIC_DEST_FIELD(kvm_apic_id(apic)); } static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda) @@ -606,6 +615,7 @@ static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda) && (logical_id & mda & 0xffff); logical_id = GET_APIC_LOGICAL_ID(logical_id); + mda = GET_APIC_DEST_FIELD(mda); switch (kvm_apic_get_reg(apic, APIC_DFR)) { case APIC_DFR_FLAT: @@ -620,10 +630,26 @@ static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda) } } +/* KVM APIC implementation has two quirks + * - dest always begins at 0 while xAPIC MDA has offset 24, + * - IOxAPIC messages have to be delivered (directly) to x2APIC. + */ +static u32 +kvm_apic_mda(unsigned int dest, struct kvm_lapic *ipi, bool x2apic_dest) +{ + bool x2apic_mda = ipi ? apic_x2apic_mode(ipi) : x2apic_dest; + + if (!ipi && dest == APIC_BROADCAST) + dest = X2APIC_BROADCAST; + + return x2apic_mda ? dest : SET_APIC_DEST_FIELD(dest); +} + bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source, int short_hand, unsigned int dest, int dest_mode) { struct kvm_lapic *target = vcpu->arch.apic; + u32 mda = kvm_apic_mda(dest, source, apic_x2apic_mode(target)); apic_debug("target %p, source %p, dest 0x%x, " "dest_mode 0x%x, short_hand 0x%x\n", @@ -633,9 +659,9 @@ bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source, switch (short_hand) { case APIC_DEST_NOSHORT: if (dest_mode == APIC_DEST_PHYSICAL) - return kvm_apic_match_physical_addr(target, dest); + return kvm_apic_match_physical_addr(target, mda); else - return kvm_apic_match_logical_addr(target, dest); + return kvm_apic_match_logical_addr(target, mda); case APIC_DEST_SELF: return target == source; case APIC_DEST_ALLINC:
In mixed modes, we musn't deliver xAPIC IPIs like x2APIC and vice versa. Instead of preserving the information in apic_send_ipi(), we regain it by converting all destinations into correct APIC MDA in the slow path. This allows easier reasoning about subsequent matching. kvm_apic_broadcast() had an interesting design decision: it didn't consider IOxAPIC 0xff as broadcast in x2APIC mode ... everything worked because IOxAPIC can't set that in physical mode and logical mode considered it as a message for first 8 VCPUs. This patch interprets IOxAPIC 0xff as x2APIC broadcast. Signed-off-by: Radim Kr?má? <rkrcmar@redhat.com> --- arch/x86/kvm/lapic.c | 40 +++++++++++++++++++++++++++++++++------- 1 file changed, 33 insertions(+), 7 deletions(-)