kernel/tools/testing/selftests/kvm/aarch64/debug-exceptions.c, branch linux-6.2.y

Merge remote-tracking branch 'kvm/queue' into HEAD

2022-12-12T20:54:07Z

x86 Xen-for-KVM: * Allow the Xen runstate information to cross a page boundary * Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured * add support for 32-bit guests in SCHEDOP_poll x86 fixes: * One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). * Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. * Clean up the MSR filter docs. * Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. * Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. * Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. * Advertise (on AMD) that the SMM_CTL MSR is not supported * Remove unnecessary exports Selftests: * Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. * Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). * Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. * Introduce actual atomics for clear/set_bit() in selftests Documentation: * Remove deleted ioctls from documentation * Various fixes

Merge tag 'kvmarm-6.2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

2022-12-09T08:12:12Z

KVM/arm64 updates for 6.2 - Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. - Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on. - Merge the pKVM shadow vcpu state tracking that allows the hypervisor to have its own view of a vcpu, keeping that state private. - Add support for the PMUv3p5 architecture revision, bringing support for 64bit counters on systems that support it, and fix the no-quite-compliant CHAIN-ed counter support for the machines that actually exist out there. - Fix a handful of minor issues around 52bit VA/PA support (64kB pages only) as a prefix of the oncoming support for 4kB and 16kB pages. - Add/Enable/Fix a bunch of selftests covering memslots, breakpoints, stage-2 faults and access tracking. You name it, we got it, we probably broke it. - Pick a small set of documentation and spelling fixes, because no good merge window would be complete without those. As a side effect, this tag also drags: - The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring series - A shared branch with the arm64 tree that repaints all the system registers to match the ARM ARM's naming, and resulting in interesting conflicts

KVM: arm64: selftests: Enable single-step without a "full" ucall()

2022-12-02T18:22:31Z

Add a new ucall hook, GUEST_UCALL_NONE(), to allow tests to make ucalls without allocating a ucall struct, and use it to enable single-step in ARM's debug-exceptions test. Like the disable single-step path, the enabling path also needs to ensure that no exclusive access sequences are attempted after enabling single-step, as the exclusive monitor is cleared on ERET from the debug exception taken to EL2. The test currently "works" because clear_bit() isn't actually an atomic operation... yet. Signed-off-by: Sean Christopherson Message-Id: <20221119013450.2643007-4-seanjc@google.com> Signed-off-by: Paolo Bonzini

KVM: selftests: Automatically do init_ucall() for non-barebones VMs

2022-11-17T00:58:51Z

Do init_ucall() automatically during VM creation to kill two (three?) birds with one stone. First, initializing ucall immediately after VM creations allows forcing aarch64's MMIO ucall address to immediately follow memslot0. This is still somewhat fragile as tests could clobber the MMIO address with a new memslot, but it's safe-ish since tests have to be conversative when accounting for memslot0. And this can be hardened in the future by creating a read-only memslot for the MMIO page (KVM ARM exits with MMIO if the guest writes to a read-only memslot). Add a TODO to document that selftests can and should use a memslot for the ucall MMIO (doing so requires yet more rework because tests assumes thay can use all memslots except memslot0). Second, initializing ucall for all VMs prepares for making ucall initialization meaningful on all architectures. aarch64 is currently the only arch that needs to do any setup, but that will change in the future by switching to a pool-based implementation (instead of the current stack-based approach). Lastly, defining the ucall MMIO address from common code will simplify switching all architectures (except s390) to a common MMIO-based ucall implementation (if there's ever sufficient motivation to do so). Cc: Oliver Upton Reviewed-by: Andrew Jones Tested-by: Peter Gonda Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221006003409.649993-4-seanjc@google.com

KVM: arm64: selftests: Disable single-step without relying on ucall()

2022-11-17T00:58:14Z

Automatically disable single-step when the guest reaches the end of the verified section instead of using an explicit ucall() to ask userspace to disable single-step. An upcoming change to implement a pool-based scheme for ucall() will add an atomic operation (bit test and set) in the guest ucall code, and if the compiler generate "old school" atomics, e.g. 40e57c: c85f7c20 ldxr x0, [x1] 40e580: aa100011 orr x17, x0, x16 40e584: c80ffc31 stlxr w15, x17, [x1] 40e588: 35ffffaf cbnz w15, 40e57c <__aarch64_ldset8_sync+0x1c> the guest will hang as the local exclusive monitor is reset by eret, i.e. the stlxr will always fail due to the debug exception taken to EL2. Link: https://lore.kernel.org/all/20221006003409.649993-8-seanjc@google.com Cc: Oliver Upton Cc: Marc Zyngier Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221117002350.2178351-3-seanjc@google.com Reviewed-by: Oliver Upton

KVM: arm64: selftests: Disable single-step with correct KVM define

2022-11-17T00:57:59Z

Disable single-step by setting debug.control to KVM_GUESTDBG_ENABLE, not to SINGLE_STEP_DISABLE. The latter is an arbitrary test enum that just happens to have the same value as KVM_GUESTDBG_ENABLE, and so effectively disables single-step debug. No functional change intended. Cc: Reiji Watanabe Fixes: b18e4d4aebdd ("KVM: arm64: selftests: Add a test case for KVM_GUESTDBG_SINGLESTEP") Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221117002350.2178351-2-seanjc@google.com Reviewed-by: Oliver Upton

KVM: selftests: Add atoi_positive() and atoi_non_negative() for input validation

2022-11-16T18:03:24Z

Many KVM selftests take command line arguments which are supposed to be positive (>0) or non-negative (>=0). Some tests do these validation and some missed adding the check. Add atoi_positive() and atoi_non_negative() to validate inputs in selftests before proceeding to use those values. Signed-off-by: Vipin Sharma Reviewed-by: Sean Christopherson Link: https://lore.kernel.org/r/20221103191719.1559407-7-vipinsh@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Add atoi_paranoid() to catch errors missed by atoi()

2022-11-16T18:03:24Z

atoi() doesn't detect errors. There is no way to know that a 0 return is correct conversion or due to an error. Introduce atoi_paranoid() to detect errors and provide correct conversion. Replace all atoi() calls with atoi_paranoid(). Signed-off-by: Vipin Sharma Suggested-by: David Matlack Suggested-by: Sean Christopherson Reviewed-by: Sean Christopherson Link: https://lore.kernel.org/r/20221103191719.1559407-4-vipinsh@google.com Signed-off-by: Sean Christopherson

KVM: arm64: selftests: Test with every breakpoint/watchpoint

2022-11-10T19:03:54Z

Currently, the debug-exceptions test always uses only {break,watch}point#0 and the highest numbered context-aware breakpoint. Modify the test to use all {break,watch}points and context-aware breakpoints supported on the system. Signed-off-by: Reiji Watanabe Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221020054202.2119018-10-reijiw@google.com

KVM: arm64: selftests: Add a test case for a linked watchpoint

2022-11-10T19:03:54Z

Currently, the debug-exceptions test doesn't have a test case for a linked watchpoint. Add a test case for the linked watchpoint to the test. The new test case uses the highest numbered context-aware breakpoint (for Context ID match), and the watchpoint#0, which is linked to the context-aware breakpoint. Signed-off-by: Reiji Watanabe Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221020054202.2119018-9-reijiw@google.com