diff options
| author | Nikita Leshenko <nikita.leshchenko@oracle.com> | 2017-11-05 15:52:33 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-03 17:04:26 +0100 |
| commit | 77e1eb750f4172f0718a6d770798b0ab9eeeb8d6 (patch) | |
| tree | d55a597e5e4104c5852ae1993904815f6fdc002e /arch | |
| parent | 3ee7ae2bb537e54d3f6ce7120c5cc39957bec930 (diff) | |
KVM: x86: ioapic: Preserve read-only values in the redirection table
[ Upstream commit b200dded0a6974a3b69599832b2203483920ab25 ]
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>
Reviewed-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/ioapic.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c index 403dd464965c..d380111351c0 100644 --- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -268,6 +268,7 @@ 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) { @@ -290,6 +291,9 @@ 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; @@ -297,6 +301,8 @@ 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 |