Re: [PATCH] KVM: arm64: Fix the upper limit of the walker range

Mark Brown
2025-01-16T02:07:39Z

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On Thu, Jan 16, 2025 at 01:16:40AM +0000, Mark Brown wrote:
> On Tue, Jan 14, 2025 at 02:50:51PM +0000, Sebastian Ene wrote:
>
> > Prevent the walker from running into weeds when walking an
> > entire address range.
>
> The KVM page_fault_test selftest started failing in next-20250115 on
> at least n1sdp and TX2 in VHE mode and a bisect seems to point to this
> change. The bisect only just finished, I've done no further
> investigation.

We're also seeing pKVM fail to initialise on a range of platforms with:

[ 0.156289] kvm [1]: nv: 557 coarse grained trap handlers
[ 0.156984] kvm [1]: IPA Size Limit: 40 bits
[ 0.182467] kvm [1]: Failed to init hyp memory protectionV

Full log at:

https://lava.sirena.org.uk/scheduler/job/1067264#L743

bisect log:

git bisect start
# status: waiting for both good and bad commits
# bad: [e7bb221a638962d487231ac45a6699fb9bb8f9fa] Add linux-next specific files for 20250115
git bisect bad e7bb221a638962d487231ac45a6699fb9bb8f9fa
# status: waiting for good commit(s), bad commit known
# good: [7b90deb712bbacdf8aa1fc01bf155cab5c21d98a] Merge branch 'for-linux-next-fixes' of https://gitlab.freedesktop.org/drm/misc/kernel.git
git bisect good 7b90deb712bbacdf8aa1fc01bf155cab5c21d98a
# good: [5f78eb69f34a94a82ff763b0eae49b6227b0b298] Merge branch 'main' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
git bisect good 5f78eb69f34a94a82ff763b0eae49b6227b0b298
# good: [825975f20474f1a6d68c0338d832ac5adaeed8b7] Merge branch 'master' of git://git.code.sf.net/p/tomoyo/tomoyo.git
git bisect good 825975f20474f1a6d68c0338d832ac5adaeed8b7
# bad: [f8ea9541257c3f2de0e6024aa4f7f9b2ba374e9e] Merge branch 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
git bisect bad f8ea9541257c3f2de0e6024aa4f7f9b2ba374e9e
# good: [9b8df195bf092153caa81b40160a0f4a766471e2] Merge branch 'non-rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
git bisect good 9b8df195bf092153caa81b40160a0f4a766471e2
# bad: [24808e495053d0fe90b27eef1f0d3cc8a3db5445] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git
git bisect bad 24808e495053d0fe90b27eef1f0d3cc8a3db5445
# bad: [a8293f931a58022b9e6ac7a45718bee25331cb87] Merge branch 'riscv_kvm_next' of https://github.com/kvm-riscv/linux.git
git bisect bad a8293f931a58022b9e6ac7a45718bee25331cb87
# good: [e880b16efb78f9c7449239a76814aeb015daf2a1] Merge branch kvm-arm64/pkvm-fixed-features-6.14 into kvmarm-master/next
git bisect good e880b16efb78f9c7449239a76814aeb015daf2a1
# good: [a1caf40a7a2c732cec1a33ec7e23d816e9103ac7] Merge branch kvm-arm64/coresight-6.14 into kvmarm-master/next
git bisect good a1caf40a7a2c732cec1a33ec7e23d816e9103ac7
# good: [a066bad89c6c79890bb8f45aef8662dcd0562a62] Merge tag 'kvm-selftests-treewide-6.14' of https://github.com/kvm-x86/linux into HEAD
git bisect good a066bad89c6c79890bb8f45aef8662dcd0562a62
# good: [af79caa83f6aa41e9092292a2ba7f701e57353ec] RISC-V: KVM: Add new exit statstics for redirected traps
git bisect good af79caa83f6aa41e9092292a2ba7f701e57353ec
# bad: [f922030f1c8541f76a103fee39ce38f15ba00c93] Merge branch kvm-arm64/misc-6.14 into kvmarm-master/next
git bisect bad f922030f1c8541f76a103fee39ce38f15ba00c93
# good: [36f998de853cfad60508dfdfb41c9c40a2245f19] KVM: arm64: nv: Apply RESx settings to sysreg reset values
git bisect good 36f998de853cfad60508dfdfb41c9c40a2245f19
# good: [0b7ff31fba40a61cfb341c8eea1540aaa6f256b9] Merge branch kvm-arm64/nv-resx-fixes-6.14 into kvmarm-master/next
git bisect good 0b7ff31fba40a61cfb341c8eea1540aaa6f256b9
# bad: [bc9e4ec6e98838314c07575a5fbc06755d21913c] KVM: arm64: Fix the upper limit of the walker range
git bisect bad bc9e4ec6e98838314c07575a5fbc06755d21913c
# first bad commit: [bc9e4ec6e98838314c07575a5fbc06755d21913c] KVM: arm64: Fix the upper limit of the walker range

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