Subject: [Xen-devel] [ovmf baseline-only test] 71952: all

This run is configured for baseline tests only.

flight 71952 ovmf real [real]

Perfect :-)
All tests in this flight passed as required
version targeted for testing:
ovmf 9e2a8e928995c3b1bb664b73fd59785055c6b5f6
baseline version:
ovmf 4cf3f37c87ba1f9d58072444bd735e40e4779e70

Last test of basis 71951 2017-08-08 17:47:30 Z 0 days
Testing same since 71952 2017-08-09 01:17:17 Z 0 days 1 attempts

People who touched revisions under test:
Dhiru Kholia <[email protected]>
Laszlo Ersek <[email protected]>

build-amd64-xsm pass
build-i386-xsm pass
build-amd64 pass
build-i386 pass
build-amd64-libvirt pass
build-i386-libvirt pass
build-amd64-pvops pass
build-i386-pvops pass
test-amd64-amd64-xl-qemuu-ovmf-amd64 pass
test-amd64-i386-xl-qemuu-ovmf-amd64 pass

sg-report-flight on
logs: /home/osstest/logs
images: /home/osstest/images

Logs, config files, etc. are available at

Test harness code can be found at;a=summary

Push not applicable.

commit 9e2a8e928995c3b1bb664b73fd59785055c6b5f6
Author: Laszlo Ersek <[email protected]>
Date: Sun Aug 6 11:20:02 2017 +0200

OvmfPkg/AcpiPlatformDxe: short-circuit the transfer of an empty S3_CONTEXT

In commit 805762252733 ("OvmfPkg/AcpiPlatformDxe: save fw_cfg boot script
with QemuFwCfgS3Lib", 2017-02-23), we replaced the explicit S3 boot script
manipulation in TransferS3ContextToBootScript() with a call to
QemuFwCfgS3CallWhenBootScriptReady(). (Passing AppendFwCfgBootScript() as

QemuFwCfgS3CallWhenBootScriptReady() checks for fw_cfg DMA up-front, and
bails with RETURN_NOT_FOUND if fw_cfg DMA is missing.

(This is justified as the goal of QemuFwCfgS3Lib is to "enable[] driver
modules [...] to produce fw_cfg DMA operations that are to be replayed at
S3 resume time".)

In turn, if QemuFwCfgS3CallWhenBootScriptReady() fails, then
OvmfPkg/AcpiPlatformDxe rolls back any earlier linker/loader script
processing, and falls back to the built-in ACPI tables.

(This is also justified because failure to save WRITE_POINTER commands for
replaying at S3 resume implies failure to process the linker/loader script

Calling QemuFwCfgS3CallWhenBootScriptReady() from
TransferS3ContextToBootScript() *unconditionally* is wrong however. For
the case when the linker/loader script contains no WRITE_POINTER commands,
the call perpetuated an earlier side effect, and introduced another one:

(1) On machine types that provide fw_cfg DMA (i.e., 2.5+),
QemuFwCfgS3CallWhenBootScriptReady() would succeed, and allocate
workspace for the boot script opcodes in reserved memory. However, no
opcodes would actually be produced in the AppendFwCfgBootScript()
callback, due to lack of any WRITE_POINTER commands.

This waste of reserved memory had been introduced in earlier commit
df73df138d9d ("OvmfPkg/AcpiPlatformDxe: replay
QEMU_LOADER_WRITE_POINTER commands at S3", 2017-02-09).

(2) On machine types that lack fw_cfg DMA (i.e., 2.4 and earlier),
TransferS3ContextToBootScript() would now fail the linker/loader
script for no reason.

(Note that QEMU itself prevents adding devices that depend on
WRITE_POINTER if the machine type lacks fw_cfg DMA:

$ qemu-system-x86_64 -M pc-q35-2.4 -device vmgenid

qemu-system-x86_64: -device vmgenid: vmgenid requires DMA write
support in fw_cfg, which this machine type does not provide)

Short-circuit an empty S3_CONTEXT in TransferS3ContextToBootScript() by
dropping S3_CONTEXT on the floor. This is compatible with the current
contract of the function as it constitutes a transfer of ownership.

Regression (2) was found and reported by Dhiru Kholia as an OSX guest boot
failure on the "pc-q35-2.4" machine type:[email protected]

Dhiru bisected the issue to commit 805762252733.

Cc: Dhiru Kholia <[email protected]>
Cc: Jordan Justen <[email protected]>
Fixes: df73df138d9d53f7f7570f4fe97a6cde941a2656
Fixes: 805762252733bb67bc5157f0137c64e010724c77
Reported-by: Dhiru Kholia <[email protected]>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <[email protected]>
Tested-by: Dhiru Kholia <[email protected]>
Reviewed-by: Jordan Justen <[email protected]>

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