A guest cannot access quadrants 1 or 2 as this would result in an exception. Thus introduce the hcall H_COPY_TOFROM_GUEST to be used by a guest when it wants to perform an access to quadrants 1 or 2, for example when it wants to access memory for one of its nested guests.
Also provide an implementation for the kvm-hv module. Signed-off-by: Suraj Jitindar Singh <sjitindarsi...@gmail.com> --- arch/powerpc/include/asm/hvcall.h | 1 + arch/powerpc/include/asm/kvm_book3s.h | 4 ++ arch/powerpc/kvm/book3s_64_mmu_radix.c | 7 ++-- arch/powerpc/kvm/book3s_hv.c | 6 ++- arch/powerpc/kvm/book3s_hv_nested.c | 75 ++++++++++++++++++++++++++++++++++ 5 files changed, 89 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index 33a4fc891947..463c63a9fcf1 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -335,6 +335,7 @@ #define H_SET_PARTITION_TABLE 0xF800 #define H_ENTER_NESTED 0xF804 #define H_TLB_INVALIDATE 0xF808 +#define H_COPY_TOFROM_GUEST 0xF80C /* Values for 2nd argument to H_SET_MODE */ #define H_SET_MODE_RESOURCE_SET_CIABR 1 diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index ea94110bfde4..720483733bb2 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -188,6 +188,9 @@ extern int kvmppc_book3s_hcall_implemented(struct kvm *kvm, unsigned long hc); extern int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, unsigned long ea, unsigned long dsisr); +extern unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid, + gva_t eaddr, void *to, void *from, + unsigned long n); extern long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to, unsigned long n); extern long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, @@ -302,6 +305,7 @@ long kvmhv_nested_init(void); void kvmhv_nested_exit(void); void kvmhv_vm_nested_init(struct kvm *kvm); long kvmhv_set_partition_table(struct kvm_vcpu *vcpu); +long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu); void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1); void kvmhv_release_all_nested(struct kvm *kvm); long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu); diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index e1e3ef710bd0..da89d10e5886 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -29,9 +29,9 @@ */ static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 }; -static unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid, - gva_t eaddr, void *to, void *from, - unsigned long n) +unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid, + gva_t eaddr, void *to, void *from, + unsigned long n) { unsigned long quadrant, ret = n; int old_pid, old_lpid; @@ -82,6 +82,7 @@ static unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid, return ret; } +EXPORT_SYMBOL_GPL(__kvmhv_copy_tofrom_guest_radix); static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to, void *from, unsigned long n) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 2280bc4778f5..bd07f9b7c5e8 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -996,7 +996,11 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) if (nesting_enabled(vcpu->kvm)) ret = kvmhv_do_nested_tlbie(vcpu); break; - + case H_COPY_TOFROM_GUEST: + ret = H_FUNCTION; + if (nesting_enabled(vcpu->kvm)) + ret = kvmhv_copy_tofrom_guest_nested(vcpu); + break; default: return RESUME_HOST; } diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c index 991f40ce4eea..f54301fcfbe4 100644 --- a/arch/powerpc/kvm/book3s_hv_nested.c +++ b/arch/powerpc/kvm/book3s_hv_nested.c @@ -462,6 +462,81 @@ long kvmhv_set_partition_table(struct kvm_vcpu *vcpu) } /* + * Handle the H_COPY_TOFROM_GUEST hcall. + * r4 = L1 lpid of nested guest + * r5 = pid + * r6 = eaddr to access + * r7 = to buffer (L1 gpa) + * r8 = from buffer (L1 gpa) + * r9 = n bytes to copy + */ +long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu) +{ + struct kvm_nested_guest *gp; + int l1_lpid = kvmppc_get_gpr(vcpu, 4); + int pid = kvmppc_get_gpr(vcpu, 5); + gva_t eaddr = kvmppc_get_gpr(vcpu, 6); + void *gp_to = (void *) kvmppc_get_gpr(vcpu, 7); + void *gp_from = (void *) kvmppc_get_gpr(vcpu, 8); + void *buf; + unsigned long n = kvmppc_get_gpr(vcpu, 9); + bool is_load = !!gp_to; + long rc; + + if (gp_to && gp_from) /* One must be NULL to determine the direction */ + return H_PARAMETER; + + if (eaddr & (0xFFFUL << 52)) + return H_PARAMETER; + + buf = kzalloc(n, GFP_KERNEL); + if (!buf) + return H_NO_MEM; + + gp = kvmhv_get_nested(vcpu->kvm, l1_lpid, false); + if (!gp) { + rc = H_PARAMETER; + goto out_free; + } + + mutex_lock(&gp->tlb_lock); + + if (is_load) { + /* Load from the nested guest into our buffer */ + rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid, + eaddr, buf, NULL, n); + if (rc) + goto not_found; + + /* Write what was loaded into our buffer back to the L1 guest */ + rc = kvmppc_st(vcpu, (ulong *) &gp_to, n, buf, true); + if (rc) + goto not_found; + } else { + /* Load the data to be stored from the L1 guest into our buf */ + rc = kvmppc_ld(vcpu, (ulong *) &gp_from, n, buf, true); + if (rc) + goto not_found; + + /* Store from our buffer into the nested guest */ + rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid, + eaddr, NULL, buf, n); + if (rc) + goto not_found; + } + +out_unlock: + mutex_unlock(&gp->tlb_lock); + kvmhv_put_nested(gp); +out_free: + kfree(buf); + return rc; +not_found: + rc = H_NOT_FOUND; + goto out_unlock; +} + +/* * Reload the partition table entry for a guest. * Caller must hold gp->tlb_lock. */ -- 2.13.6