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| author | Bibo Mao <maobibo@loongson.cn> | 2024-05-06 17:00:47 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2024-05-06 17:00:47 +0300 |
| commit | 74c16b2e2b0c3b193324f47300fd30cf03a606b7 (patch) | |
| tree | d44f09842b78696110c39849488eb5a4adf2e8d9 /arch/loongarch/Kconfig | |
| parent | e33bda7ee50c3c20d80f5ca6dc5ca2cd37863518 (diff) | |
| download | linux-74c16b2e2b0c3b193324f47300fd30cf03a606b7.tar.xz | |
LoongArch: KVM: Add PV IPI support on guest side
PARAVIRT config option and PV IPI is added for the guest side, function
pv_ipi_init() is used to add IPI sending and IPI receiving hooks. This
function firstly checks whether system runs in VM mode, and if kernel
runs in VM mode, it will call function kvm_para_available() to detect
the current hypervirsor type (now only KVM type detection is supported).
The paravirt functions can work only if current hypervisor type is KVM,
since there is only KVM supported on LoongArch now.
PV IPI uses virtual IPI sender and virtual IPI receiver functions. With
virtual IPI sender, IPI message is stored in memory rather than emulated
HW. IPI multicast is also supported, and 128 vcpus can received IPIs
at the same time like X86 KVM method. Hypercall method is used for IPI
sending.
With virtual IPI receiver, HW SWI0 is used rather than real IPI HW.
Since VCPU has separate HW SWI0 like HW timer, there is no trap in IPI
interrupt acknowledge. Since IPI message is stored in memory, there is
no trap in getting IPI message.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/Kconfig')
| -rw-r--r-- | arch/loongarch/Kconfig | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 54ad04dacdee..42331d9a8dd7 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -632,6 +632,15 @@ config RANDOMIZE_BASE_MAX_OFFSET source "kernel/livepatch/Kconfig" +config PARAVIRT + bool "Enable paravirtualization code" + depends on AS_HAS_LVZ_EXTENSION + help + This changes the kernel so it can modify itself when it is run + under a hypervisor, potentially improving performance significantly + over full virtualization. However, when run without a hypervisor + the kernel is theoretically slower and slightly larger. + endmenu config ARCH_SELECT_MEMORY_MODEL |