| Message ID | 20171105135233.34572-6-nikita.leshchenko@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2017-11-05 21:52 GMT+08:00 Nikita Leshenko <nikita.leshchenko@oracle.com>: > According to 82093AA (IOAPIC) manual, Remote IRR and Delivery Status are > read-only. QEMU implements the bits as RO in commit 479c2a1cb7fb > ("ioapic: keep RO bits for IOAPIC entry"). > > Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com> > Reviewed-by: Liran Alon <liran.alon@oracle.com> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> > --- > arch/x86/kvm/ioapic.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c > index 163d340ee5f8..4e822ad363f3 100644 > --- a/arch/x86/kvm/ioapic.c > +++ b/arch/x86/kvm/ioapic.c > @@ -276,6 +276,7 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) > { > unsigned index; > bool mask_before, mask_after; > + int old_remote_irr, old_delivery_status; > union kvm_ioapic_redirect_entry *e; > > switch (ioapic->ioregsel) { > @@ -298,6 +299,9 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) > return; > e = &ioapic->redirtbl[index]; > mask_before = e->fields.mask; > + /* Preserve read-only fields */ > + old_remote_irr = e->fields.remote_irr; > + old_delivery_status = e->fields.delivery_status; > if (ioapic->ioregsel & 1) { > e->bits &= 0xffffffff; > e->bits |= (u64) val << 32; > @@ -305,6 +309,8 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) > e->bits &= ~0xffffffffULL; > e->bits |= (u32) val; > } > + e->fields.remote_irr = old_remote_irr; > + e->fields.delivery_status = old_delivery_status; > > /* > * Some OSes (Linux, Xen) assume that Remote IRR bit will > -- > 2.13.3 >
Reviewed-by: Steve Rutherford <srutherford@google.com> On Sun, Nov 5, 2017 at 7:20 PM, Wanpeng Li <kernellwp@gmail.com> wrote: > 2017-11-05 21:52 GMT+08:00 Nikita Leshenko <nikita.leshchenko@oracle.com>: >> According to 82093AA (IOAPIC) manual, Remote IRR and Delivery Status are >> read-only. QEMU implements the bits as RO in commit 479c2a1cb7fb >> ("ioapic: keep RO bits for IOAPIC entry"). >> >> Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com> >> Reviewed-by: Liran Alon <liran.alon@oracle.com> >> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > > Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> > >> --- >> arch/x86/kvm/ioapic.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c >> index 163d340ee5f8..4e822ad363f3 100644 >> --- a/arch/x86/kvm/ioapic.c >> +++ b/arch/x86/kvm/ioapic.c >> @@ -276,6 +276,7 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) >> { >> unsigned index; >> bool mask_before, mask_after; >> + int old_remote_irr, old_delivery_status; >> union kvm_ioapic_redirect_entry *e; >> >> switch (ioapic->ioregsel) { >> @@ -298,6 +299,9 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) >> return; >> e = &ioapic->redirtbl[index]; >> mask_before = e->fields.mask; >> + /* Preserve read-only fields */ >> + old_remote_irr = e->fields.remote_irr; >> + old_delivery_status = e->fields.delivery_status; >> if (ioapic->ioregsel & 1) { >> e->bits &= 0xffffffff; >> e->bits |= (u64) val << 32; >> @@ -305,6 +309,8 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) >> e->bits &= ~0xffffffffULL; >> e->bits |= (u32) val; >> } >> + e->fields.remote_irr = old_remote_irr; >> + e->fields.delivery_status = old_delivery_status; >> >> /* >> * Some OSes (Linux, Xen) assume that Remote IRR bit will >> -- >> 2.13.3 >>
diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c index 163d340ee5f8..4e822ad363f3 100644 --- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -276,6 +276,7 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) { unsigned index; bool mask_before, mask_after; + int old_remote_irr, old_delivery_status; union kvm_ioapic_redirect_entry *e; switch (ioapic->ioregsel) { @@ -298,6 +299,9 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) return; e = &ioapic->redirtbl[index]; mask_before = e->fields.mask; + /* Preserve read-only fields */ + old_remote_irr = e->fields.remote_irr; + old_delivery_status = e->fields.delivery_status; if (ioapic->ioregsel & 1) { e->bits &= 0xffffffff; e->bits |= (u64) val << 32; @@ -305,6 +309,8 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) e->bits &= ~0xffffffffULL; e->bits |= (u32) val; } + e->fields.remote_irr = old_remote_irr; + e->fields.delivery_status = old_delivery_status; /* * Some OSes (Linux, Xen) assume that Remote IRR bit will
According to 82093AA (IOAPIC) manual, Remote IRR and Delivery Status are read-only. QEMU implements the bits as RO in commit 479c2a1cb7fb ("ioapic: keep RO bits for IOAPIC entry"). Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- arch/x86/kvm/ioapic.c | 6 ++++++ 1 file changed, 6 insertions(+)