When SEV is enabled, every debug message printed by OVMF to the
QEMU debug port traps from the guest to QEMU character by character
because "REP OUTSB" cannot be used by IoWriteFifo8. Furthermore,
when OVMF is built with the DEBUG_VERBOSE bit (value 0x00400000)
enabled in "gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel", then the
OvmfPkg/IoMmuDxe driver, and the OvmfPkg/Library/BaseMemEncryptSevLib
library instance that is built into it, produce a huge amount of
log messages. Therefore, in SEV guests, the boot time impact is huge
(about 45 seconds _additional_ time spent writing to the debug port).
While these messages are very useful for analyzing guest behavior,
most of the time the user won't be capturing the OVMF debug log.
In fact libvirt does not provide a method for configuring log capture;
users that wish to do this (or are instructed to do this) have to resort
to <qemu:arg>.
The debug console device provides a handy detection mechanism; when read,
it returns 0xE9 (which is very much unlike the 0xFF that is returned by
an unused port). Use it to skip the possibly expensive OUT instructions
when the debug I/O port isn't plugged anywhere.
For SEC, the debug port has to be read before each full message.
However:
- if the debug port is available, then reading one byte before writing
a full message isn't tragic, especially because SEC doesn't print many
messages
- if the debug port is not available, then reading one byte instead of
writing a full message is still a win.
Contributed-under: TianoCore Contribution Agreement 1.0
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen (Intel address) <jordan.l.justen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
The next patch will want to add a global variable to
PlatformDebugLibIoPort, but this is not suitable for the SEC
phase, because SEC runs from read-only flash. The solution is
to have two library instances, one for SEC and another
for all other firmware phases. This patch adds the "plumbing"
for the SEC library instance, separating the INF files and
moving the constructor to a separate C source file.
Contributed-under: TianoCore Contribution Agreement 1.1
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen (Intel address) <jordan.l.justen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Remove Uefi.h, which includes UefiSpec.h, and change the
return value to match the RETURN_STATUS type.
Contributed-under: TianoCore Contribution Agreement 1.1
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen (Intel address) <jordan.l.justen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Since commit 19c6d9feaa ("MdePkg: Expand BaseIoLibIntrinsic (IoLib
class) library", 2017-01-14), IoWriteFifo8() has been widely available to
modules. Use it to print debug messages and assertion failures to the QEMU
debug port, rather than open-coded loops.
In the general case this speeds up logging, because debug messages will
now trap to QEMU once per message (as opposed to once per character), due
to "REP OUTSB" in "MdePkg/Library/BaseIoLibIntrinsic/*/IoFifoSev.nasm".
In SEV guests, there is no speedup (SEV doesn't support the REP prefix).
SEV is detected internally to BaseIoLibIntrinsic.
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Brijesh Singh <brijesh.singh@amd.com>
The LineNumber parameter of the DebugAssert() function has type UINTN.
DebugAssert() passes it to AsciiSPrint() with the %d conversion specifier
at the moment, but %d would require an INT32 argument.
Fix this by casting LineNumber to UINT64, also employing the matching
decimal conversion specifier, %Lu.
(Another possibility would be to cast LineNumber to INT32, but a
UINTN->INT32 cast is not value preserving, generally speaking.)
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Scott Duplichan <scott@notabs.org>
Reported-by: Scott Duplichan <scott@notabs.org>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18173 6f19259b-4bc3-4df7-8a09-765794883524
Implement new API DebugPrintLevelEnabled() to base on PCD PcdFixedDebugPrintErrorLevel.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16797 6f19259b-4bc3-4df7-8a09-765794883524
This patch adds support for a debug console on the same port that is used
by SeaBIOS. This makes it easier to debug OVMF, because it does not mix
debug and serial output on the same device. It also makes it easier to
leave some of the debug messages on even in release builds.
To enable it, pass "-debugcon stdio -global isa-debugcon.iobase=0x402" to
QEMU.
The new mechanism is enabled by default, but a regular serial console can
be chosen by adding -D DEBUG_ON_SERIAL_PORT to the build options.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
[jordan.l.justen@intel.com: MAX_DEBUG_MESSAGE_LENGTH=>0x100, p=>Ptr]
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13562 6f19259b-4bc3-4df7-8a09-765794883524
Paolo Bonzini
Laszlo Ersek
Liming Gao
jljusten