diff options
| -rw-r--r-- | Documentation/virt/kvm/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/virt/kvm/ppc-pv.rst (renamed from Documentation/virt/kvm/ppc-pv.txt) | 26 |
2 files changed, 19 insertions, 8 deletions
diff --git a/Documentation/virt/kvm/index.rst b/Documentation/virt/kvm/index.rst index 123385d0a74a..d0e17e717461 100644 --- a/Documentation/virt/kvm/index.rst +++ b/Documentation/virt/kvm/index.rst @@ -16,6 +16,7 @@ KVM mmu msr nested-vmx + ppc-pv vcpu-requests arm/index diff --git a/Documentation/virt/kvm/ppc-pv.txt b/Documentation/virt/kvm/ppc-pv.rst index e26115ce4258..5fdb907670be 100644 --- a/Documentation/virt/kvm/ppc-pv.txt +++ b/Documentation/virt/kvm/ppc-pv.rst @@ -1,3 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================================= The PPC KVM paravirtual interface ================================= @@ -34,8 +37,9 @@ up the hypercall. To call a hypercall, just call these instructions. The parameters are as follows: + ======== ================ ================ Register IN OUT - + ======== ================ ================ r0 - volatile r3 1st parameter Return code r4 2nd parameter 1st output value @@ -47,6 +51,7 @@ The parameters are as follows: r10 8th parameter 7th output value r11 hypercall number 8th output value r12 - volatile + ======== ================ ================ Hypercall definitions are shared in generic code, so the same hypercall numbers apply for x86 and powerpc alike with the exception that each KVM hypercall @@ -54,11 +59,13 @@ also needs to be ORed with the KVM vendor code which is (42 << 16). Return codes can be as follows: + ==== ========================= Code Meaning - + ==== ========================= 0 Success 12 Hypercall not implemented <0 Error + ==== ========================= The magic page ============== @@ -72,7 +79,7 @@ desired location. The first parameter indicates the effective address when the MMU is enabled. The second parameter indicates the address in real mode, if applicable to the target. For now, we always map the page to -4096. This way we can access it using absolute load and store functions. The following -instruction reads the first field of the magic page: +instruction reads the first field of the magic page:: ld rX, -4096(0) @@ -93,8 +100,10 @@ a bitmap of available features inside the magic page. The following enhancements to the magic page are currently available: + ============================ ======================================= KVM_MAGIC_FEAT_SR Maps SR registers r/w in the magic page KVM_MAGIC_FEAT_MAS0_TO_SPRG7 Maps MASn, ESR, PIR and high SPRGs + ============================ ======================================= For enhanced features in the magic page, please check for the existence of the feature before using them! @@ -121,8 +130,8 @@ when entering the guest or don't have any impact on the hypervisor's behavior. The following bits are safe to be set inside the guest: - MSR_EE - MSR_RI + - MSR_EE + - MSR_RI If any other bit changes in the MSR, please still use mtmsr(d). @@ -138,9 +147,9 @@ guest. Implementing any of those mappings is optional, as the instruction traps also act on the shared page. So calling privileged instructions still works as before. +======================= ================================ From To -==== == - +======================= ================================ mfmsr rX ld rX, magic_page->msr mfsprg rX, 0 ld rX, magic_page->sprg0 mfsprg rX, 1 ld rX, magic_page->sprg1 @@ -173,7 +182,7 @@ mtsrin rX, rY b <special mtsrin section> [BookE only] wrteei [0|1] b <special wrteei section> - +======================= ================================ Some instructions require more logic to determine what's going on than a load or store instruction can deliver. To enable patching of those, we keep some @@ -191,6 +200,7 @@ for example. Hypercall ABIs in KVM on PowerPC ================================= + 1) KVM hypercalls (ePAPR) These are ePAPR compliant hypercall implementation (mentioned above). Even |