8 Commits
Author SHA1 Message Date
Matthew Barnes c8754cbc1d CHANGELOG: Add note about xAPIC destination mode change
Fixes: dcbf8210f3 ('x86/APIC: Switch flat driver to use phys dst for ext ints')
Signed-off-by: Matthew Barnes <matthew.barnes@cloud.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
2024-11-11 13:19:27 +01:00
Matthew Barnes dcbf8210f3 x86/APIC: Switch flat driver to use phys dst for ext ints
External interrupts via logical delivery mode in xAPIC do not benefit
from targeting multiple CPUs and instead simply bloat up the vector
space.

However the xAPIC flat driver currently uses logical delivery for
external interrupts.

This patch switches the xAPIC flat driver to use physical destination
mode for external interrupts, instead of logical destination mode.

This patch also applies the following non-functional changes:
- Remove now unused logical flat functions
- Expand GENAPIC_FLAT and GENAPIC_PHYS macros, and delete them.

Resolves: https://gitlab.com/xen-project/xen/-/issues/194
Signed-off-by: Matthew Barnes <matthew.barnes@cloud.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
2024-10-09 09:54:48 +02:00
Matthew Barnes 9b0d2465c8 x86/APIC: Remove x2APIC pure cluster mode
With the introduction of mixed x2APIC mode (using cluster addressing for
IPIs and physical for external interrupts) the use of pure cluster mode
doesn't have any benefit.

Remove the mode itself, leaving only the code required for logical
addressing when sending IPIs.

Resolves: https://gitlab.com/xen-project/xen/-/issues/189
Signed-off-by: Matthew Barnes <matthew.barnes@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
2024-09-24 18:57:38 +01:00
Matthew Barnes 5afb11ac40 x86/cpufeatures: Add new cpuid features in SPR to featureset
Upon running `xen-cpuid -v` on a host machine with Sapphire Rapids
within Dom0, there exist unrecognised features.

This patch adds these features as macros to the CPU featureset,
disabled by default.

Signed-off-by: Matthew Barnes <matthew.barnes@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2024-09-06 14:42:18 +01:00
Matthew Barnes 08aacc392d x86/emul: Fix misaligned IO breakpoint behaviour in PV guests
When hardware breakpoints are configured on misaligned IO ports, the
hardware will mask the addresses based on the breakpoint width during
comparison.

For PV guests, misaligned IO breakpoints do not behave the same way, and
therefore yield different results.

This patch tweaks the emulation of IO breakpoints for PV guests such
that they reproduce the same behaviour as hardware.

Fixes: bec9e32050 ("x86: emulate I/O port access breakpoints")
Signed-off-by: Matthew Barnes <matthew.barnes@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-08-08 13:27:50 +02:00
Matthew Barnes e92a453c8d tools/lsevtchn: Use errno macro to handle hypercall error cases
Currently, lsevtchn aborts its event channel enumeration when it hits
an event channel that is owned by Xen.

lsevtchn does not distinguish between different hypercall errors, which
results in lsevtchn missing potential relevant event channels with
higher port numbers.

Use the errno macro to distinguish between hypercall errors, and
continue event channel enumeration if the hypercall error is not
critical to enumeration.

Signed-off-by: Matthew Barnes <matthew.barnes@cloud.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2024-08-02 08:43:57 +02:00
Matthew Barnes e42e4d8c3e tools/misc: xen-hvmcrash: Inject #DF instead of overwriting RIP
xen-hvmcrash would previously save records, overwrite the instruction
pointer with a bogus value, and then restore them to crash a domain
just enough to cause the guest OS to memdump.

This approach is found to be unreliable when tested on a guest running
Windows 10 x64, with some executions doing nothing at all.

Another approach would be to trigger NMIs. This approach is found to be
unreliable when tested on Linux (Ubuntu 22.04), as Linux will ignore
NMIs if it is not configured to handle such.

Injecting a double fault abort to all vCPUs is found to be more
reliable at crashing and invoking memdumps from Windows and Linux
domains.

This patch modifies the xen-hvmcrash tool to inject #DF to all vCPUs
belonging to the specified domain, instead of overwriting RIP.

Signed-off-by: Matthew Barnes <matthew.barnes@cloud.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2024-07-22 10:50:03 +01:00
Matthew Barnes c5746b021e x86/ioapic: Fix signed shifts in io_apic.c
There exists bitshifts in the IOAPIC code where signed integers are
shifted to the left by up to 31 bits, which is undefined behaviour.

This patch fixes this by changing the integers from signed to unsigned.

Signed-off-by: Matthew Barnes <matthew.barnes@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
2024-06-21 15:09:26 +01:00