Introduce bsd-user-qemu and run-{shell,user}-riscv64-purecap targets. #264

kwitaszczyk · 2021-12-04T17:00:12Z

The targets use QEMU code from the qemu-cheri-bsd-user branch.

Examples:

Build the BSD user mode:
```
./cheribuild.py bsd-user-qemu
```

Run a CheriABI CHERI-RISC-V command:

./cheribuild.py run-user-riscv64-purecap \
    --run-user/command  \
    '/zdata/cheri/output/rootfs-riscv64-purecap/bin/cheribsdtest-purecap-dynamic -a'

Run a CheriABI CHERI-RISC-V command with the root directory changed to a sysroot:

sudo ./cheribuild.py --allow-running-as-root run-user-riscv64-purecap \
    --run-user/chroot --run-user/command \
    'cheribsdtest-purecap-dynamic -a'

Run a CheriABI CHERI-RISC-V shell in a jail with the root directory changed to a sysroot and devfs(8) mounted:

sudo ./cheribuild.py --allow-running-as-root run-shell-riscv64-purecap \
    --run-shell/jail --run-shell/jail-extra-args mount.devfs

jrtc27 · 2021-12-08T15:57:31Z

README.md

@@ -151,6 +151,8 @@ For the `cheribsd`, `disk-image` and `run` targets the hybrid vs purecap distinc
 - `freebsd-<architecture>` builds and installs [freebsd/freebsd](https://github.com/freebsd/freebsd).
 - `disk-image-freebsd-<architecture>` creates a FreeBSD disk-image.
 - `run-freebsd-<architecture>` launches QEMU with the FreeBSD disk image.
+- `run-shell-<architecture>` launches a shell with the QEMU user mode in a CheriBSD sysroot.


As mentioned on Slack in the past, I think run-user-shell does a better job of namespacing it as a qemu-user thing, since arguably run does get you a shell (once you log in)

Done: 10d522b .

Besides run-user-shell, we also have run-user to execute an arbitrary command. What do you think about that target name? I wonder if we should remove run-user-shell and only have run-user which by default executes /bin/sh, unless --run-user/command is specified.

pycheribuild/projects/build_qemu.py

jrtc27 · 2021-12-08T16:04:18Z

pycheribuild/projects/build_qemu.py

+    repository = GitRepository("https://github.com/CTSRD-CHERI/qemu.git",
+                               default_branch="qemu-cheri-bsd-user",
+                               force_branch=True)
+    native_install_dir = DefaultInstallDir.BSD_USER_SDK


You shouldn't need a whole new enum for this, just copy upstream-qemu's approach?

BuildUpstreamQEMU's way is quite complex. Wouldn't be it easier to maintain a separate enum for this?

Instead, we could add a comment the enum should be removed once the BSD user mode is merged to qemu-cheri (which can take quite a while).

Does this install anything other than the qemu-user binaries? If not we could reuse the same installation directory?

jrtc27 · 2021-12-08T16:07:53Z

pycheribuild/projects/build_qemu.py

+    hide_options_from_help = True
+
+    @classmethod
+    def qemu_cheri_binary(cls, caller: SimpleProject, xtarget: CrossCompileTarget = None, absolute_path=True):


This is going to need to be a separate method as otherwise we won't be able to have a single target that builds both

I'm not sure if we're going to be able to build both a system mode and a user mode with a single configure. The BSD user mode needs to be static for Poudriere (it copies a single binary to a jail).

Would we want to build system modes with --static? If not, would we want to add --static per mode or target?

pycheribuild/projects/run_qemu.py

pycheribuild/qemu_utils.py

kwitaszczyk

I'm aware the branch must be rebased before it can be merged to qemu-cheri. I'll do it once the current changes are accepted as I'd have to force push the rebase and hence ruin this review.

kwitaszczyk · 2022-02-22T14:00:19Z

README.md

@@ -151,6 +151,8 @@ For the `cheribsd`, `disk-image` and `run` targets the hybrid vs purecap distinc
 - `freebsd-<architecture>` builds and installs [freebsd/freebsd](https://github.com/freebsd/freebsd).
 - `disk-image-freebsd-<architecture>` creates a FreeBSD disk-image.
 - `run-freebsd-<architecture>` launches QEMU with the FreeBSD disk image.
+- `run-shell-<architecture>` launches a shell with the QEMU user mode in a CheriBSD sysroot.


Done: 10d522b .

Besides run-user-shell, we also have run-user to execute an arbitrary command. What do you think about that target name? I wonder if we should remove run-user-shell and only have run-user which by default executes /bin/sh, unless --run-user/command is specified.

pycheribuild/qemu_utils.py

kwitaszczyk · 2022-02-22T14:15:39Z

pycheribuild/projects/build_qemu.py

+    repository = GitRepository("https://github.com/CTSRD-CHERI/qemu.git",
+                               default_branch="qemu-cheri-bsd-user",
+                               force_branch=True)
+    native_install_dir = DefaultInstallDir.BSD_USER_SDK


BuildUpstreamQEMU's way is quite complex. Wouldn't be it easier to maintain a separate enum for this?

Instead, we could add a comment the enum should be removed once the BSD user mode is merged to qemu-cheri (which can take quite a while).

kwitaszczyk · 2022-02-22T14:57:37Z

pycheribuild/projects/build_qemu.py

+    hide_options_from_help = True
+
+    @classmethod
+    def qemu_cheri_binary(cls, caller: SimpleProject, xtarget: CrossCompileTarget = None, absolute_path=True):


I'm not sure if we're going to be able to build both a system mode and a user mode with a single configure. The BSD user mode needs to be static for Poudriere (it copies a single binary to a jail).

Would we want to build system modes with --static? If not, would we want to add --static per mode or target?

pycheribuild/projects/run_qemu.py

pycheribuild/projects/build_qemu.py

The target builds the QEMU CheriABI user mode targets from the qemu-cheri-bsd-user branch in CTSRD-CHERI/QEMU and installs it in a separate SDK directory. This target doesn't use SMB and hence doesn't require SMB support.

A run-<architecture>-shell target launches a shell with the QEMU user mode in a CheriBSD sysroot. * Since the run-<architecture>-shell targets run a QEMU user mode binary, different QEMU flags are required, as opposed to the run-<architecture> targets. Modify the QemuOptions class to provide separate methods to construct argument lists for a system or a user mode binary; * Instead of using the LaunchQEMUBase class, introduce the LaunchBsdUserQEMUBase class that runs a user mode binary; * Instead of using the LaunchCheriBSD class, introduce the LaunchCheriBSDShell class that creates run-<architecture> targets with the "-shell" suffix; * Describe the run-<architecture>-shell targets in README.

A run-<architecture>-exec target executes a command passed with an option --exec/command. Additionally, one of the following options can be used: * --exec/chroot tells cheribuild to change a root directory to a sysroot before executing the command; * --exec/jail tells cheribuild to enter a jail with a sysroot before executing the command. The flags --exec/{chroot,jail} require cheribuild to be run as root. At the moment, --allow-running-as-root can be used to run cheribuild with sudo but this option shouldn't be used without the flags --exec/{chroot,jail}. Additionally, --skip-update is recommended when carefully using --allow-running-as-root.

@jrtc27

* Rename the targets to run-{shell,user}-<architecture> for consistency with other targets; * Describe the run-user-<architecture> in README. Pointed out by: @jrtc27

The jail-extra-args options allow to pass extra jail parameters to jail(8), e.g. to mount devfs(8).

BuildSystemQEMU is a parent class for all classes for system-mode targets. Thanks to this class, two issues are resolved: * BuildQEMUBase was adding --disable-bsd-user to configure flags also for user-mode targets; * BuildQEMU was adding morello-softmmu to the default targets if a QEMU branch includes Morello support. BuildBsdUserQEMU can manage its own list of targets and not use configuration flags only related to the system mode now.

Extend the bsd-user-qemu target to build BSD user modes for all targets we're interested in: aarch64, riscv64, riscv64c. Morello will be added to the above list once it's working.

* Rename the target to indiciate with a 'user' subword it's related to the BSD user mode (built with the bsd-user-qemu cheribuild target); * Update class names to match target names better. Pointed out by: jrtc27

Allow to specify an ELF interpreter path for the run-user and run-user-shell targets. The interpreter path can be different than an encoded one in an ELF binary in multi-ABI environments, e.g. a Poudriere jail.

Map the guest address space not to overlap with a host address space.

Pointed out by: jrtc27

AbstractLaunchFreeBSDProgram was the only child class of the LaunchBsdUserQEMUBase class. Instead of introducing another abstraction, move AbstractLaunchFreeBSDProgram login into LaunchBsdUserQEMUBase. Pointed out by: jrtc27

Set the default value of a command to execute with the user mode to /bin/sh within a rootfs.

The command should be computed depending on a target context. In case of run-user-shell, we'd like to append a rootfs path if the shell is not executed with chroot nor jail. Pointed out by: jrtc27

Reduce a number of additional abstractions required for the user mode support that should be eventually removed once the user mode is merged into the qemu-cheri branch. This change uses a hack to always pass --disabled-bsd-user to configure and later pass --enable-bsd-user to overwrite it. Pointed out by: jrtc27

kwitaszczyk self-assigned this Dec 4, 2021

kwitaszczyk requested a review from jrtc27 December 8, 2021 11:58

jrtc27 reviewed Dec 8, 2021

View reviewed changes

kwitaszczyk commented Feb 22, 2022

View reviewed changes

kwitaszczyk requested a review from jrtc27 March 2, 2022 11:42

kwitaszczyk force-pushed the qemu-cheri-bsd-user branch from 87d2f95 to b557b57 Compare May 13, 2022 14:48

kwitaszczyk added 19 commits March 27, 2023 16:20

Introduce the bsd-user-qemu target.

b23da30

The target builds the QEMU CheriABI user mode targets from the qemu-cheri-bsd-user branch in CTSRD-CHERI/QEMU and installs it in a separate SDK directory. This target doesn't use SMB and hence doesn't require SMB support.

Rename run-<architecture>-{shell,exec} targets.

8c67455

* Rename the targets to run-{shell,user}-<architecture> for consistency with other targets; * Describe the run-user-<architecture> in README. Pointed out by: @jrtc27

Introduce --run-{shell,user}/jail-extra-args.

3bb34a6

The jail-extra-args options allow to pass extra jail parameters to jail(8), e.g. to mount devfs(8).

Add QEMU BSD user mode options for Jenkins.

efe4075

Mock the BSD user-mode SDK directory path.

6a3da25

Make Flake8 happy.

b664350

Build BSD user modes for aarch64 and riscv64.

be4fd63

Extend the bsd-user-qemu target to build BSD user modes for all targets we're interested in: aarch64, riscv64, riscv64c. Morello will be added to the above list once it's working.

Build the Morello user mode by default.

ddfd600

Rename the run-shell target to run-user-shell.

d466115

* Rename the target to indiciate with a 'user' subword it's related to the BSD user mode (built with the bsd-user-qemu cheribuild target); * Update class names to match target names better. Pointed out by: jrtc27

Add an interpreter path option.

553bf45

Allow to specify an ELF interpreter path for the run-user and run-user-shell targets. The interpreter path can be different than an encoded one in an ELF binary in multi-ABI environments, e.g. a Poudriere jail.

Map a guest address space at 0x100000000.

c6d823e

Map the guest address space not to overlap with a host address space.

Remove an unused argument.

cd8b16e

Pointed out by: jrtc27

Remove AbstractLaunchFreeBSDProgram.

7427478

AbstractLaunchFreeBSDProgram was the only child class of the LaunchBsdUserQEMUBase class. Instead of introducing another abstraction, move AbstractLaunchFreeBSDProgram login into LaunchBsdUserQEMUBase. Pointed out by: jrtc27

Set a default value for --run-user/command.

48dc528

Set the default value of a command to execute with the user mode to /bin/sh within a rootfs.

Compute a command within a target context.

d4c322e

The command should be computed depending on a target context. In case of run-user-shell, we'd like to append a rootfs path if the shell is not executed with chroot nor jail. Pointed out by: jrtc27

kwitaszczyk force-pushed the qemu-cheri-bsd-user branch from b557b57 to 1590f85 Compare March 27, 2023 16:22

arichardson changed the base branch from master to main April 4, 2023 21:40

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Introduce bsd-user-qemu and run-{shell,user}-riscv64-purecap targets. #264

Introduce bsd-user-qemu and run-{shell,user}-riscv64-purecap targets. #264

kwitaszczyk commented Dec 4, 2021

jrtc27 Dec 8, 2021

kwitaszczyk Feb 22, 2022

jrtc27 Dec 8, 2021

kwitaszczyk Feb 22, 2022

arichardson Apr 4, 2023

jrtc27 Dec 8, 2021

kwitaszczyk Feb 22, 2022

kwitaszczyk left a comment

kwitaszczyk Feb 22, 2022

kwitaszczyk Feb 22, 2022

kwitaszczyk Feb 22, 2022

Introduce bsd-user-qemu and run-{shell,user}-riscv64-purecap targets. #264

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Introduce bsd-user-qemu and run-{shell,user}-riscv64-purecap targets. #264

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