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| author | Huacai Chen <chenhc@lemote.com> | 2020-05-23 10:56:37 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-06-04 20:50:39 +0300 |
| commit | f21db3090de2c056728dee76d5fb66343aaf6dd1 (patch) | |
| tree | 4b5789f4ca1a6f9d4c9f3aa83faac86d190aab4b /arch/mips/kvm/emulate.c | |
| parent | 3f51d8fcac7a0925fb1222d932cb3baa776b1e79 (diff) | |
| download | linux-f21db3090de2c056728dee76d5fb66343aaf6dd1.tar.xz | |
KVM: MIPS: Add Loongson-3 Virtual IPI interrupt support
This patch add Loongson-3 Virtual IPI interrupt support in the kernel.
The current implementation of IPI emulation in QEMU is based on GIC for
MIPS, but Loongson-3 doesn't use GIC. Furthermore, IPI emulation in QEMU
is too expensive for performance (because of too many context switches
between Host and Guest). With current solution, the IPI delay may even
cause RCU stall warnings in a multi-core Guest. So, we design a faster
solution that emulate IPI interrupt in kernel (only used by Loongson-3
now).
Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Co-developed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <1590220602-3547-11-git-send-email-chenhc@lemote.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/mips/kvm/emulate.c')
| -rw-r--r-- | arch/mips/kvm/emulate.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c index 7ccf9b096783..4fa93d6a2ec5 100644 --- a/arch/mips/kvm/emulate.c +++ b/arch/mips/kvm/emulate.c @@ -1600,6 +1600,7 @@ enum emulation_result kvm_mips_emulate_store(union mips_instruction inst, struct kvm_run *run, struct kvm_vcpu *vcpu) { + int r; enum emulation_result er; u32 rt; void *data = run->mmio.data; @@ -1666,9 +1667,18 @@ enum emulation_result kvm_mips_emulate_store(union mips_instruction inst, goto out_fail; } - run->mmio.is_write = 1; vcpu->mmio_needed = 1; + run->mmio.is_write = 1; vcpu->mmio_is_write = 1; + + r = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, + run->mmio.phys_addr, run->mmio.len, data); + + if (!r) { + vcpu->mmio_needed = 0; + return EMULATE_DONE; + } + return EMULATE_DO_MMIO; out_fail: @@ -1681,6 +1691,7 @@ enum emulation_result kvm_mips_emulate_load(union mips_instruction inst, u32 cause, struct kvm_run *run, struct kvm_vcpu *vcpu) { + int r; enum emulation_result er; unsigned long curr_pc; u32 op, rt; @@ -1745,6 +1756,16 @@ enum emulation_result kvm_mips_emulate_load(union mips_instruction inst, run->mmio.is_write = 0; vcpu->mmio_is_write = 0; + + r = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, + run->mmio.phys_addr, run->mmio.len, run->mmio.data); + + if (!r) { + kvm_mips_complete_mmio_load(vcpu, run); + vcpu->mmio_needed = 0; + return EMULATE_DONE; + } + return EMULATE_DO_MMIO; } |