From a4a0f2524acc2c602cadd8e743be19d86f3a746b Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Fri, 20 Sep 2013 14:52:44 +1000 Subject: KVM: PPC: Book3S PR: Allow guest to use 64k pages This adds the code to interpret 64k HPTEs in the guest hashed page table (HPT), 64k SLB entries, and to tell the guest about 64k pages in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed by 4k pages. This also adds another hash table to the four we have already in book3s_mmu_hpte.c to allow us to find all the PTEs that we have instantiated that match a given 64k guest page. The tlbie instruction changed starting with POWER6 to use a bit in the RB operand to indicate large page invalidations, and to use other RB bits to indicate the base and actual page sizes and the segment size. 64k pages came in slightly earlier, with POWER5++. We use one bit in vcpu->arch.hflags to indicate that the emulated cpu supports 64k pages, and another to indicate that it has the new tlbie definition. The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because the MMU capabilities depend on which CPU model we're emulating, but it is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU fd. In addition, commonly-used userspace (QEMU) calls it before setting the PVR for any VCPU. Therefore, as a best effort we look at the first vcpu in the VM and return 64k pages or not depending on its capabilities. We also make the PVR default to the host PVR on recent CPUs that support 1TB segments (and therefore multiple page sizes as well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB segment support on those CPUs. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf --- arch/powerpc/include/asm/kvm_asm.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/powerpc/include/asm/kvm_asm.h') diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h index 851bac7afa4..e2d4d467ee9 100644 --- a/arch/powerpc/include/asm/kvm_asm.h +++ b/arch/powerpc/include/asm/kvm_asm.h @@ -123,6 +123,8 @@ #define BOOK3S_HFLAG_SLB 0x2 #define BOOK3S_HFLAG_PAIRED_SINGLE 0x4 #define BOOK3S_HFLAG_NATIVE_PS 0x8 +#define BOOK3S_HFLAG_MULTI_PGSIZE 0x10 +#define BOOK3S_HFLAG_NEW_TLBIE 0x20 #define RESUME_FLAG_NV (1<<0) /* Reload guest nonvolatile state? */ #define RESUME_FLAG_HOST (1<<1) /* Resume host? */ -- cgit v1.2.3-70-g09d2 From 44a3add86311bb9d060d795bcdcdc9b8c7a35bd0 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Fri, 4 Oct 2013 21:45:04 +1000 Subject: KVM: PPC: Book3S HV: Better handling of exceptions that happen in real mode When an interrupt or exception happens in the guest that comes to the host, the CPU goes to hypervisor real mode (MMU off) to handle the exception but doesn't change the MMU context. After saving a few registers, we then clear the "in guest" flag. If, for any reason, we get an exception in the real-mode code, that then gets handled by the normal kernel exception handlers, which turn the MMU on. This is disastrous if the MMU is still set to the guest context, since we end up executing instructions from random places in the guest kernel with hypervisor privilege. In order to catch this situation, we define a new value for the "in guest" flag, KVM_GUEST_MODE_HOST_HV, to indicate that we are in hypervisor real mode with guest MMU context. If the "in guest" flag is set to this value, we branch off to an emergency handler. For the moment, this just does a branch to self to stop the CPU from doing anything further. While we're here, we define another new flag value to indicate that we are in a HV guest, as distinct from a PR guest. This will be useful when we have a kernel that can support both PR and HV guests concurrently. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf --- arch/powerpc/include/asm/kvm_asm.h | 2 ++ arch/powerpc/kvm/book3s_hv_rmhandlers.S | 31 +++++++++++++++++++++++++------ 2 files changed, 27 insertions(+), 6 deletions(-) (limited to 'arch/powerpc/include/asm/kvm_asm.h') diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h index e2d4d467ee9..1bd92fd43cf 100644 --- a/arch/powerpc/include/asm/kvm_asm.h +++ b/arch/powerpc/include/asm/kvm_asm.h @@ -138,6 +138,8 @@ #define KVM_GUEST_MODE_NONE 0 #define KVM_GUEST_MODE_GUEST 1 #define KVM_GUEST_MODE_SKIP 2 +#define KVM_GUEST_MODE_GUEST_HV 3 +#define KVM_GUEST_MODE_HOST_HV 4 #define KVM_INST_FETCH_FAILED -1 diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 6e3370f42a6..84105eb18a0 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -387,6 +387,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206) mtspr SPRN_DAR, r5 mtspr SPRN_DSISR, r6 + li r6, KVM_GUEST_MODE_HOST_HV + stb r6, HSTATE_IN_GUEST(r13) + BEGIN_FTR_SECTION /* Restore AMR and UAMOR, set AMOR to all 1s */ ld r5,VCPU_AMR(r4) @@ -690,7 +693,7 @@ fast_guest_return: mtspr SPRN_HSRR1,r11 /* Activate guest mode, so faults get handled by KVM */ - li r9, KVM_GUEST_MODE_GUEST + li r9, KVM_GUEST_MODE_GUEST_HV stb r9, HSTATE_IN_GUEST(r13) /* Enter guest */ @@ -750,6 +753,14 @@ kvmppc_interrupt: */ /* abuse host_r2 as third scratch area; we get r2 from PACATOC(r13) */ std r9, HSTATE_HOST_R2(r13) + + lbz r9, HSTATE_IN_GUEST(r13) + cmpwi r9, KVM_GUEST_MODE_HOST_HV + beq kvmppc_bad_host_intr + /* We're now back in the host but in guest MMU context */ + li r9, KVM_GUEST_MODE_HOST_HV + stb r9, HSTATE_IN_GUEST(r13) + ld r9, HSTATE_KVM_VCPU(r13) /* Save registers */ @@ -801,10 +812,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) std r3, VCPU_GPR(R13)(r9) std r4, VCPU_LR(r9) - /* Unset guest mode */ - li r0, KVM_GUEST_MODE_NONE - stb r0, HSTATE_IN_GUEST(r13) - stw r12,VCPU_TRAP(r9) /* Save HEIR (HV emulation assist reg) in last_inst @@ -1198,6 +1205,10 @@ BEGIN_FTR_SECTION mtspr SPRN_AMR,r6 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206) + /* Unset guest mode */ + li r0, KVM_GUEST_MODE_NONE + stb r0, HSTATE_IN_GUEST(r13) + /* Switch DSCR back to host value */ BEGIN_FTR_SECTION mfspr r8, SPRN_DSCR @@ -1400,7 +1411,7 @@ fast_interrupt_c_return: stw r8, VCPU_LAST_INST(r9) /* Unset guest mode. */ - li r0, KVM_GUEST_MODE_NONE + li r0, KVM_GUEST_MODE_HOST_HV stb r0, HSTATE_IN_GUEST(r13) b guest_exit_cont @@ -1949,3 +1960,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) lwz r7,VCPU_VRSAVE(r4) mtspr SPRN_VRSAVE,r7 blr + +/* + * We come here if we get any exception or interrupt while we are + * executing host real mode code while in guest MMU context. + * For now just spin, but we should do something better. + */ +kvmppc_bad_host_intr: + b . -- cgit v1.2.3-70-g09d2