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| author | Suraj Jitindar Singh <sjitindarsingh@gmail.com> | 2018-12-14 16:29:08 +1100 |
|---|---|---|
| committer | Paul Mackerras <paulus@ozlabs.org> | 2018-12-17 11:33:50 +1100 |
| commit | 873db2cd9a6d7f017d8f4c637cf4166c038c27d6 (patch) | |
| tree | 596e2a4b4937accebc613f2e3866db3a07d90053 /arch/powerpc/include/asm/kvm_host.h | |
| parent | cc6929cc842cceee714c66cd55346b1a9f114a98 (diff) | |
| download | linux-873db2cd9a6d7f017d8f4c637cf4166c038c27d6.tar.bz2 | |
KVM: PPC: Book3S HV: Allow passthrough of an emulated device to an L2 guest
Allow for a device which is being emulated at L0 (the host) for an L1
guest to be passed through to a nested (L2) guest.
The existing kvmppc_hv_emulate_mmio function can be used here. The main
challenge is that for a load the result must be stored into the L2 gpr,
not an L1 gpr as would normally be the case after going out to qemu to
complete the operation. This presents a challenge as at this point the
L2 gpr state has been written back into L1 memory.
To work around this we store the address in L1 memory of the L2 gpr
where the result of the load is to be stored and use the new io_gpr
value KVM_MMIO_REG_NESTED_GPR to indicate that this is a nested load for
which completion must be done when returning back into the kernel. Then
in kvmppc_complete_mmio_load() the resultant value is written into L1
memory at the location of the indicated L2 gpr.
Note that we don't currently let an L1 guest emulate a device for an L2
guest which is then passed through to an L3 guest.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc/include/asm/kvm_host.h')
| -rw-r--r-- | arch/powerpc/include/asm/kvm_host.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index fac6f631ed29..7a2483a139cf 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -793,6 +793,7 @@ struct kvm_vcpu_arch { /* For support of nested guests */ struct kvm_nested_guest *nested; u32 nested_vcpu_id; + gpa_t nested_io_gpr; #endif #ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING @@ -827,6 +828,8 @@ struct kvm_vcpu_arch { #define KVM_MMIO_REG_FQPR 0x00c0 #define KVM_MMIO_REG_VSX 0x0100 #define KVM_MMIO_REG_VMX 0x0180 +#define KVM_MMIO_REG_NESTED_GPR 0xffc0 + #define __KVM_HAVE_ARCH_WQP #define __KVM_HAVE_CREATE_DEVICE |