From 210552c1bfe83122a480673660d5ca9821c944ae Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 5 Mar 2013 03:18:00 +0000 Subject: ARM: KVM: add support for minimal host vs guest profiling In order to be able to correctly profile what is happening on the host, we need to be able to identify when we're running on the guest, and log these events differently. Perf offers a simple way to register callbacks into KVM. Mimic what x86 does and enjoy being able to profile your KVM host. Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 0c4e643d939..78813b8fad3 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -207,4 +207,7 @@ static inline void __cpu_init_hyp_mode(unsigned long long pgd_ptr, kvm_call_hyp((void *)pgd_low, pgd_high, hyp_stack_ptr, vector_ptr); } +int kvm_perf_init(void); +int kvm_perf_teardown(void); + #endif /* __ARM_KVM_HOST_H__ */ -- cgit v1.2.3-18-g5258 From 2fb410596ca917fe6419be61ee5bc1782b17d947 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 12 Apr 2013 19:12:03 +0100 Subject: ARM: KVM: move to a KVM provided HYP idmap After the HYP page table rework, it is pretty easy to let the KVM code provide its own idmap, rather than expecting the kernel to provide it. It takes actually less code to do so. Acked-by: Will Deacon Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/idmap.h | 1 - arch/arm/include/asm/kvm_mmu.h | 1 - 2 files changed, 2 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h index 1a66f907e5c..bf863edb517 100644 --- a/arch/arm/include/asm/idmap.h +++ b/arch/arm/include/asm/idmap.h @@ -8,7 +8,6 @@ #define __idmap __section(.idmap.text) noinline notrace extern pgd_t *idmap_pgd; -extern pgd_t *hyp_pgd; void setup_mm_for_reboot(void); diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 970f3b5fa10..3c71a1d4b7a 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -21,7 +21,6 @@ #include #include -#include /* * We directly use the kernel VA for the HYP, as we can directly share -- cgit v1.2.3-18-g5258 From 4f728276fbf1e043010485d7e9275082a1c3d650 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 12 Apr 2013 19:12:05 +0100 Subject: ARM: KVM: rework HYP page table freeing There is no point in freeing HYP page tables differently from Stage-2. They now have the same requirements, and should be dealt with the same way. Promote unmap_stage2_range to be The One True Way, and get rid of a number of nasty bugs in the process (good thing we never actually called free_hyp_pmds before...). Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_mmu.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 3c71a1d4b7a..92eb20d5794 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -32,7 +32,7 @@ int create_hyp_mappings(void *from, void *to); int create_hyp_io_mappings(void *from, void *to, phys_addr_t); -void free_hyp_pmds(void); +void free_hyp_pgds(void); int kvm_alloc_stage2_pgd(struct kvm *kvm); void kvm_free_stage2_pgd(struct kvm *kvm); -- cgit v1.2.3-18-g5258 From 5a677ce044f18a341ab942e23516e52ad89f7687 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 12 Apr 2013 19:12:06 +0100 Subject: ARM: KVM: switch to a dual-step HYP init code Our HYP init code suffers from two major design issues: - it cannot support CPU hotplug, as we tear down the idmap very early - it cannot perform a TLB invalidation when switching from init to runtime mappings, as pages are manipulated from PL1 exclusively The hotplug problem mandates that we keep two sets of page tables (boot and runtime). The TLB problem mandates that we're able to transition from one PGD to another while in HYP, invalidating the TLBs in the process. To be able to do this, we need to share a page between the two page tables. A page that will have the same VA in both configurations. All we need is a VA that has the following properties: - This VA can't be used to represent a kernel mapping. - This VA will not conflict with the physical address of the kernel text The vectors page seems to satisfy this requirement: - The kernel never maps anything else there - The kernel text being copied at the beginning of the physical memory, it is unlikely to use the last 64kB (I doubt we'll ever support KVM on a system with something like 4MB of RAM, but patches are very welcome). Let's call this VA the trampoline VA. Now, we map our init page at 3 locations: - idmap in the boot pgd - trampoline VA in the boot pgd - trampoline VA in the runtime pgd The init scenario is now the following: - We jump in HYP with four parameters: boot HYP pgd, runtime HYP pgd, runtime stack, runtime vectors - Enable the MMU with the boot pgd - Jump to a target into the trampoline page (remember, this is the same physical page!) - Now switch to the runtime pgd (same VA, and still the same physical page!) - Invalidate TLBs - Set stack and vectors - Profit! (or eret, if you only care about the code). Note that we keep the boot mapping permanently (it is not strictly an idmap anymore) to allow for CPU hotplug in later patches. Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 31 +++++++++++++++++++------------ arch/arm/include/asm/kvm_mmu.h | 24 +++++++++++++++++++++--- 2 files changed, 40 insertions(+), 15 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 78813b8fad3..6c2a35da867 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -188,23 +188,30 @@ int kvm_arm_coproc_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *); int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, int exception_index); -static inline void __cpu_init_hyp_mode(unsigned long long pgd_ptr, +static inline void __cpu_init_hyp_mode(unsigned long long boot_pgd_ptr, + unsigned long long pgd_ptr, unsigned long hyp_stack_ptr, unsigned long vector_ptr) { - unsigned long pgd_low, pgd_high; - - pgd_low = (pgd_ptr & ((1ULL << 32) - 1)); - pgd_high = (pgd_ptr >> 32ULL); - /* - * Call initialization code, and switch to the full blown - * HYP code. The init code doesn't need to preserve these registers as - * r1-r3 and r12 are already callee save according to the AAPCS. - * Note that we slightly misuse the prototype by casing the pgd_low to - * a void *. + * Call initialization code, and switch to the full blown HYP + * code. The init code doesn't need to preserve these + * registers as r0-r3 are already callee saved according to + * the AAPCS. + * Note that we slightly misuse the prototype by casing the + * stack pointer to a void *. + * + * We don't have enough registers to perform the full init in + * one go. Install the boot PGD first, and then install the + * runtime PGD, stack pointer and vectors. The PGDs are always + * passed as the third argument, in order to be passed into + * r2-r3 to the init code (yes, this is compliant with the + * PCS!). */ - kvm_call_hyp((void *)pgd_low, pgd_high, hyp_stack_ptr, vector_ptr); + + kvm_call_hyp(NULL, 0, boot_pgd_ptr); + + kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr); } int kvm_perf_init(void); diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 92eb20d5794..24b767a8cdb 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -19,17 +19,29 @@ #ifndef __ARM_KVM_MMU_H__ #define __ARM_KVM_MMU_H__ -#include -#include +#include +#include /* * We directly use the kernel VA for the HYP, as we can directly share * the mapping (HTTBR "covers" TTBR1). */ -#define HYP_PAGE_OFFSET_MASK (~0UL) +#define HYP_PAGE_OFFSET_MASK UL(~0) #define HYP_PAGE_OFFSET PAGE_OFFSET #define KERN_TO_HYP(kva) (kva) +/* + * Our virtual mapping for the boot-time MMU-enable code. Must be + * shared across all the page-tables. Conveniently, we use the vectors + * page, where no kernel data will ever be shared with HYP. + */ +#define TRAMPOLINE_VA UL(CONFIG_VECTORS_BASE) + +#ifndef __ASSEMBLY__ + +#include +#include + int create_hyp_mappings(void *from, void *to); int create_hyp_io_mappings(void *from, void *to, phys_addr_t); void free_hyp_pgds(void); @@ -44,6 +56,8 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run); void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu); phys_addr_t kvm_mmu_get_httbr(void); +phys_addr_t kvm_mmu_get_boot_httbr(void); +phys_addr_t kvm_get_idmap_vector(void); int kvm_mmu_init(void); void kvm_clear_hyp_idmap(void); @@ -113,4 +127,8 @@ static inline void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn) } } +#define kvm_flush_dcache_to_poc(a,l) __cpuc_flush_dcache_area((a), (l)) + +#endif /* !__ASSEMBLY__ */ + #endif /* __ARM_KVM_MMU_H__ */ -- cgit v1.2.3-18-g5258 From d157f4a5155f4fbd0d1da66b3d2f504c13bd194d Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 12 Apr 2013 19:12:07 +0100 Subject: ARM: KVM: perform HYP initilization for hotplugged CPUs Now that we have the necessary infrastructure to boot a hotplugged CPU at any point in time, wire a CPU notifier that will perform the HYP init for the incoming CPU. Note that this depends on the platform code and/or firmware to boot the incoming CPU with HYP mode enabled and return to the kernel by following the normal boot path (HYP stub installed). Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_mmu.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 24b767a8cdb..472ac709100 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -44,6 +44,7 @@ int create_hyp_mappings(void *from, void *to); int create_hyp_io_mappings(void *from, void *to, phys_addr_t); +void free_boot_hyp_pgd(void); void free_hyp_pgds(void); int kvm_alloc_stage2_pgd(struct kvm *kvm); -- cgit v1.2.3-18-g5258 From 17b1e31f9201fc102ee3ddd409988e47753e22f9 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 8 Apr 2013 16:47:18 +0100 Subject: ARM: KVM: add architecture specific hook for capabilities Most of the capabilities are common to both arm and arm64, but we still need to handle the exceptions. Introduce kvm_arch_dev_ioctl_check_extension, which both architectures implement (in the 32bit case, it just returns 0). Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 6c2a35da867..dcfcbf59fce 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -214,6 +214,11 @@ static inline void __cpu_init_hyp_mode(unsigned long long boot_pgd_ptr, kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr); } +static inline int kvm_arch_dev_ioctl_check_extension(long ext) +{ + return 0; +} + int kvm_perf_init(void); int kvm_perf_teardown(void); -- cgit v1.2.3-18-g5258 From 3de50da6901521f9e520b8eb47d092779512e83c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 8 Apr 2013 16:47:19 +0100 Subject: ARM: KVM: promote vfp_host pointer to generic host cpu context We use the vfp_host pointer to store the host VFP context, should the guest start using VFP itself. Actually, we can use this pointer in a more generic way to store CPU speficic data, and arm64 is using it to dump the whole host state before switching to the guest. Simply rename the vfp_host field to host_cpu_context, and the corresponding type to kvm_cpu_context_t. No change in functionnality. Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index dcfcbf59fce..57cb786a620 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -87,7 +87,7 @@ struct kvm_vcpu_fault_info { u32 hyp_pc; /* PC when exception was taken from Hyp mode */ }; -typedef struct vfp_hard_struct kvm_kernel_vfp_t; +typedef struct vfp_hard_struct kvm_cpu_context_t; struct kvm_vcpu_arch { struct kvm_regs regs; @@ -105,8 +105,10 @@ struct kvm_vcpu_arch { struct kvm_vcpu_fault_info fault; /* Floating point registers (VFP and Advanced SIMD/NEON) */ - kvm_kernel_vfp_t vfp_guest; - kvm_kernel_vfp_t *vfp_host; + struct vfp_hard_struct vfp_guest; + + /* Host FP context */ + kvm_cpu_context_t *host_cpu_context; /* VGIC state */ struct vgic_cpu vgic_cpu; -- cgit v1.2.3-18-g5258