Searched hist:eeedfe6c (Results 1 – 3 of 3) sorted by relevance
/openbmc/qemu/hw/i386/kvm/ |
H A D | xen_evtchn.h | eeedfe6c Wed Apr 12 13:50:58 CDT 2023 David Woodhouse <dwmw@amazon.co.uk> hw/xen: Simplify emulated Xen platform init
I initially put the basic platform init (overlay pages, grant tables, event channels) into mc->kvm_type because that was the earliest place that could sensibly test for xen_mode==XEN_EMULATE.
The intent was to do this early enough that we could then initialise the XenBus and other parts which would have depended on them, from a generic location for both Xen and KVM/Xen in the PC-specific code, as seen in https://lore.kernel.org/qemu-devel/20230116221919.1124201-16-dwmw2@infradead.org/
However, then the Xen on Arm patches came along, and *they* wanted to do the XenBus init from a 'generic' Xen-specific location instead: https://lore.kernel.org/qemu-devel/20230210222729.957168-4-sstabellini@kernel.org/
Since there's no generic location that covers all three, I conceded to do it for XEN_EMULATE mode in pc_basic_devices_init().
And now there's absolutely no point in having some of the platform init done from pc_machine_kvm_type(); we can move it all up to live in a single place in pc_basic_devices_init(). This has the added benefit that we can drop the separate xen_evtchn_connect_gsis() function completely, and pass just the system GSIs in directly to xen_evtchn_create().
While I'm at it, it does no harm to explicitly pass in the *number* of said GSIs, because it does make me twitch a bit to pass an array of impicit size. During the lifetime of the KVM/Xen patchset, that had already changed (albeit just cosmetically) from GSI_NUM_PINS to IOAPIC_NUM_PINS.
And document a bit better that this is for the *output* GSI for raising CPU0's events when the per-CPU vector isn't available. The fact that we create a whole set of them and then only waggle the one we're told to, instead of having a single output and only *connecting* it to the GSI that it should be connected to, is still non-intuitive for me.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org> Message-Id: <20230412185102.441523-2-dwmw2@infradead.org> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
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H A D | xen_evtchn.c | eeedfe6c Wed Apr 12 13:50:58 CDT 2023 David Woodhouse <dwmw@amazon.co.uk> hw/xen: Simplify emulated Xen platform init
I initially put the basic platform init (overlay pages, grant tables, event channels) into mc->kvm_type because that was the earliest place that could sensibly test for xen_mode==XEN_EMULATE.
The intent was to do this early enough that we could then initialise the XenBus and other parts which would have depended on them, from a generic location for both Xen and KVM/Xen in the PC-specific code, as seen in https://lore.kernel.org/qemu-devel/20230116221919.1124201-16-dwmw2@infradead.org/
However, then the Xen on Arm patches came along, and *they* wanted to do the XenBus init from a 'generic' Xen-specific location instead: https://lore.kernel.org/qemu-devel/20230210222729.957168-4-sstabellini@kernel.org/
Since there's no generic location that covers all three, I conceded to do it for XEN_EMULATE mode in pc_basic_devices_init().
And now there's absolutely no point in having some of the platform init done from pc_machine_kvm_type(); we can move it all up to live in a single place in pc_basic_devices_init(). This has the added benefit that we can drop the separate xen_evtchn_connect_gsis() function completely, and pass just the system GSIs in directly to xen_evtchn_create().
While I'm at it, it does no harm to explicitly pass in the *number* of said GSIs, because it does make me twitch a bit to pass an array of impicit size. During the lifetime of the KVM/Xen patchset, that had already changed (albeit just cosmetically) from GSI_NUM_PINS to IOAPIC_NUM_PINS.
And document a bit better that this is for the *output* GSI for raising CPU0's events when the per-CPU vector isn't available. The fact that we create a whole set of them and then only waggle the one we're told to, instead of having a single output and only *connecting* it to the GSI that it should be connected to, is still non-intuitive for me.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org> Message-Id: <20230412185102.441523-2-dwmw2@infradead.org> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
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/openbmc/qemu/hw/i386/ |
H A D | pc.c | eeedfe6c Wed Apr 12 13:50:58 CDT 2023 David Woodhouse <dwmw@amazon.co.uk> hw/xen: Simplify emulated Xen platform init
I initially put the basic platform init (overlay pages, grant tables, event channels) into mc->kvm_type because that was the earliest place that could sensibly test for xen_mode==XEN_EMULATE.
The intent was to do this early enough that we could then initialise the XenBus and other parts which would have depended on them, from a generic location for both Xen and KVM/Xen in the PC-specific code, as seen in https://lore.kernel.org/qemu-devel/20230116221919.1124201-16-dwmw2@infradead.org/
However, then the Xen on Arm patches came along, and *they* wanted to do the XenBus init from a 'generic' Xen-specific location instead: https://lore.kernel.org/qemu-devel/20230210222729.957168-4-sstabellini@kernel.org/
Since there's no generic location that covers all three, I conceded to do it for XEN_EMULATE mode in pc_basic_devices_init().
And now there's absolutely no point in having some of the platform init done from pc_machine_kvm_type(); we can move it all up to live in a single place in pc_basic_devices_init(). This has the added benefit that we can drop the separate xen_evtchn_connect_gsis() function completely, and pass just the system GSIs in directly to xen_evtchn_create().
While I'm at it, it does no harm to explicitly pass in the *number* of said GSIs, because it does make me twitch a bit to pass an array of impicit size. During the lifetime of the KVM/Xen patchset, that had already changed (albeit just cosmetically) from GSI_NUM_PINS to IOAPIC_NUM_PINS.
And document a bit better that this is for the *output* GSI for raising CPU0's events when the per-CPU vector isn't available. The fact that we create a whole set of them and then only waggle the one we're told to, instead of having a single output and only *connecting* it to the GSI that it should be connected to, is still non-intuitive for me.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org> Message-Id: <20230412185102.441523-2-dwmw2@infradead.org> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
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