Prevent stack underrun in the event of a timer interrupt storm in
LocalApicTimerDxe and 8254TimerDxe interrupt handlers by using the
helper functions provided by NestedInterruptTplLib.
This fixes the same problem as addressed in commit 239b50a86
("OvmfPkg: End timer interrupt later to avoid stack overflow under
load"), but does so without breaking nested timer interrupts.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2815
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4162
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Deferring the EOI until after the call to RestoreTPL() means that any
callbacks invoked by RestoreTPL() will run with timer interrupt
delivery disabled. If any such callbacks themselves rely on timers to
implement timeout loops, then the callbacks will get stuck in an
infinite loop from which the system will never recover.
This reverts commit 239b50a86 ("OvmfPkg: End timer interrupt later to
avoid stack overflow under load").
Cc: Paolo Bonzini <pbonzini@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4162
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3711
Discussion in https://bugzilla.tianocore.org/show_bug.cgi?id=1496 shows
that 8254TimerDxe was not written for OVMF. It was moved over from
PcAtChipsetPkg to OvmfPkg in 2019. Probably because OVMF was the only
user left.
Most likely the reason OVMF used 8254TimerDxe initially was that it could
just use the existing driver in PcAtChipsetPkg. And it simply hasn't
been changed ever.
CSM support was moved in 2019 too. (CSM support depends on 8254/8259
drivers). So 8254TimerDxe will be used when CSM_ENABLE=TRUE.
There are 4 .dsc which include the 8254Timer.
- OvmfPkg/AmdSev/AmdSevX64.dsc
- OvmfPkg/OvmfPkgIa32.dsc
- OvmfPkg/OvmfPkgIa32X64.dsc
- OvmfPkg/OvmfPkgX64.dsc
For the three OvmfPkg* configs using 8254TimerDxe with CSM_ENABLE=TRUE
and LapicTimerDxe otherwise.
For the AmdSev config it doesn't make sense to support a CSM. So use
the lapic timer unconditionally.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Suggested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3711
XenTimerDxe is a local Apic timer driver and it has nothing to do
with Xen. So rename it to LocalApicTimerDxe.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Julien Grall <julien@xen.org>
Acked-by: Anthony PERARD <anthony.perard@citrix.com
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Michael Brown
Min Xu