From de56a948b9182fbcf92cb8212f114de096c2d574 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Wed, 29 Jun 2011 00:21:34 +0000 Subject: KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf --- arch/powerpc/include/asm/reg.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/powerpc/include/asm/reg.h') diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index d879a6b9163..36a611b398c 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -189,6 +189,9 @@ #define SPRN_CTR 0x009 /* Count Register */ #define SPRN_DSCR 0x11 #define SPRN_CFAR 0x1c /* Come From Address Register */ +#define SPRN_AMR 0x1d /* Authority Mask Register */ +#define SPRN_UAMOR 0x9d /* User Authority Mask Override Register */ +#define SPRN_AMOR 0x15d /* Authority Mask Override Register */ #define SPRN_ACOP 0x1F /* Available Coprocessor Register */ #define SPRN_CTRLF 0x088 #define SPRN_CTRLT 0x098 @@ -252,6 +255,7 @@ #define LPCR_RMI 0x00000002 /* real mode is cache inhibit */ #define LPCR_HDICE 0x00000001 /* Hyp Decr enable (HV,PR,EE) */ #define SPRN_LPID 0x13F /* Logical Partition Identifier */ +#define LPID_RSVD 0x3ff /* Reserved LPID for partn switching */ #define SPRN_HMER 0x150 /* Hardware m? error recovery */ #define SPRN_HMEER 0x151 /* Hardware m? enable error recovery */ #define SPRN_HEIR 0x153 /* Hypervisor Emulated Instruction Register */ -- cgit v1.2.3-70-g09d2