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/mmu-hash64.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/include/asm/mmu-hash64.h') diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h index d865bd909c7..b445e0af4c2 100644 --- a/arch/powerpc/include/asm/mmu-hash64.h +++ b/arch/powerpc/include/asm/mmu-hash64.h @@ -90,13 +90,19 @@ extern char initial_stab[]; #define HPTE_R_PP0 ASM_CONST(0x8000000000000000) #define HPTE_R_TS ASM_CONST(0x4000000000000000) +#define HPTE_R_KEY_HI ASM_CONST(0x3000000000000000) #define HPTE_R_RPN_SHIFT 12 -#define HPTE_R_RPN ASM_CONST(0x3ffffffffffff000) -#define HPTE_R_FLAGS ASM_CONST(0x00000000000003ff) +#define HPTE_R_RPN ASM_CONST(0x0ffffffffffff000) #define HPTE_R_PP ASM_CONST(0x0000000000000003) #define HPTE_R_N ASM_CONST(0x0000000000000004) +#define HPTE_R_G ASM_CONST(0x0000000000000008) +#define HPTE_R_M ASM_CONST(0x0000000000000010) +#define HPTE_R_I ASM_CONST(0x0000000000000020) +#define HPTE_R_W ASM_CONST(0x0000000000000040) +#define HPTE_R_WIMG ASM_CONST(0x0000000000000078) #define HPTE_R_C ASM_CONST(0x0000000000000080) #define HPTE_R_R ASM_CONST(0x0000000000000100) +#define HPTE_R_KEY_LO ASM_CONST(0x0000000000000e00) #define HPTE_V_1TB_SEG ASM_CONST(0x4000000000000000) #define HPTE_V_VRMA_MASK ASM_CONST(0x4001ffffff000000) -- cgit v1.2.3-70-g09d2