bwlp/qemu.git/pc-bios/s390-ccw/jump2ipl.c, branch spice_video_codecs

pc-bios/s390-ccw: Fix inline assembly for older versions of Clang

2021-05-14T10:38:43+00:00

Clang versions before v11.0 insist on having the %rX or %cX register names instead of just a number. Since our Travis-CI is currently still using Clang v6.0, we have to fix this to avoid failing jobs. Message-Id: <20210512171550.476130-2-thuth@redhat.com> Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Thomas Huth

pc-bios/s390-ccw: Use reset_psw pointer instead of hard-coded null pointer

2021-05-09T16:14:31+00:00

When compiling the s390-ccw bios with clang, it emits a warning like this: pc-bios/s390-ccw/jump2ipl.c:86:9: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference] if (*((uint64_t *)0) & RESET_PSW_MASK) { ^~~~~~~~~~~~~~~~ pc-bios/s390-ccw/jump2ipl.c:86:9: note: consider using __builtin_trap() or qualifying pointer with 'volatile' We could add a "volatile" here to shut it up, but on the other hand, we also have a pointer variable called "reset_psw" in this file already that points to the PSW at address 0, so we can simply use that pointer variable instead. Reviewed-by: Philippe Mathieu-Daudé Message-Id: <20210423142440.582188-1-thuth@redhat.com> Reviewed-by: Janosch Frank Signed-off-by: Thomas Huth

pc-bios: s390x: Clear out leftover S390EP string

2020-11-23T08:48:45+00:00

A Linux binary will have the string "S390EP" at address 0x10008, which is important in getting the guest up off the ground. In the case of a reboot (specifically chreipl going to a new device), we should defer to the PSW at address zero for the new config, which will re-write "S390EP" from the new image. Let's clear it out at this point so that a reipl to, say, a DASD passthrough device drives the IPL path from scratch without disrupting disrupting the order of operations for other boots. Rather than hardcoding the address of this magic (again), let's define it somewhere so that the two users are visibly related. Signed-off-by: Eric Farman Message-Id: <20201120160117.59366-3-farman@linux.ibm.com> Signed-off-by: Thomas Huth

pc-bios: s390x: Use reset PSW if avaliable

2020-10-06T18:14:17+00:00

If a blob provides a reset PSW then we should use it instead of branching to the PSW address and using our own mask. Signed-off-by: Janosch Frank Reviewed-by: Thomas Huth Message-Id: <20201006094249.50640-4-frankja@linux.ibm.com> [thuth: Use Elvis operator to shorten long line] Signed-off-by: Thomas Huth

pc-bios: s390x: Save PSW rework

2020-10-06T17:57:35+00:00

We don't need to save the ipl_continue variable in lowcore and have it limited to 32 bits because of the lowcore layout. Let's move it to a new 64 bit variable and get rid of the reset info struct. Signed-off-by: Janosch Frank Reviewed-by: Thomas Huth Message-Id: <20201006094249.50640-3-frankja@linux.ibm.com> Signed-off-by: Thomas Huth

pc-bios: s390x: Use PSW masks where possible and introduce PSW_MASK_SHORT_ADDR

2020-07-02T08:00:32+00:00

Let's move some of the PSW mask defines into s390-arch.h and use them in jump2ipl.c. Also let's introduce a new constant for the address mask of 8 byte (short) PSWs. Signed-off-by: Janosch Frank Reviewed-by: David Hildenbrand Reviewed-by: Thomas Huth Message-Id: <20200624075226.92728-8-frankja@linux.ibm.com> Signed-off-by: Thomas Huth

pc-bios: s390x: Save iplb location in lowcore

2020-03-10T09:18:08+00:00

The POP states that for a list directed IPL the IPLB is stored into memory by the machine loader and its address is stored at offset 0x14 of the lowcore. ZIPL currently uses the address in offset 0x14 to access the IPLB and acquire flags about secure boot. If the IPLB address points into memory which has an unsupported mix of flags set, ZIPL will panic instead of booting the OS. As the lowcore can have quite a high entropy for a guest that did drop out of protected mode (i.e. rebooted) we encountered the ZIPL panic quite often. Signed-off-by: Janosch Frank Tested-by: Marc Hartmayer Message-Id: <20200304114231.23493-19-frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger Reviewed-by: David Hildenbrand Signed-off-by: Christian Borntraeger

pc-bios/s390x: Fix reset psw mask

2019-12-18T14:54:24+00:00

We need to set the short psw indication bit in the reset psw, as it is a short psw. Exposed by "s390x: Properly fetch and test the short psw on diag308 subc 0/1". Fixes: 962982329029 ("pc-bios/s390-ccw: do a subsystem reset before running the guest") Signed-off-by: Janosch Frank Message-Id: <20191203132813.2734-5-frankja@linux.ibm.com> Acked-by: Christian Borntraeger Signed-off-by: Cornelia Huck

pc-bios/s390-ccw/net: Use diag308 to reset machine before jumping to the OS

2018-05-02T09:27:14+00:00

The netboot firmware so far simply jumped directly into the OS kernel after the download has been completed. This, however, bears the risk that the virtio-net device still might be active in the background and incoming packets are still placed into the buffers - which could destroy memory of the now-running Linux kernel in case it did not take over the device fast enough. Also the SCLP console is not put into a well-defined state here. We should hand over the system in a clean state when jumping into the kernel, so let's use the same mechanism as it's done in the main s390-ccw firmware and reset the machine with diag308 into a clean state before jumping into the OS kernel code. To be able to share the code with the main s390-ccw firmware, the related functions are now extracted from bootmap.c into a new file called jump2ipl.c. Since we now also set the boot device schid at address 184 for the network boot device, this patch also slightly changes the way how we detect the entry points for non-ELF binary images: The code now looks for the "S390EP" magic first and then jumps to 0x10000 in case it has been found. This is necessary for booting from network devices, since the normal kernel code (where the PSW at ddress 0 points to) tries to do a block load from the boot device. This of course fails for a virtio-net device and causes the kernel to abort with a panic-PSW silently. Acked-by: Christian Borntraeger Signed-off-by: Thomas Huth