From 5cd92a9521d35013fff904d3c805323027a33d73 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Fri, 20 Sep 2013 14:52:47 +1000 Subject: [PATCH] KVM: PPC: Book3S PR: Correct errors in H_ENTER implementation The implementation of H_ENTER in PR KVM has some errors: * With H_EXACT not set, if the HPTEG is full, we return H_PTEG_FULL as the return value of kvmppc_h_pr_enter, but the caller is expecting one of the EMULATE_* values. The H_PTEG_FULL needs to go in the guest's R3 instead. * With H_EXACT set, if the selected HPTE is already valid, the H_ENTER call should return a H_PTEG_FULL error. This fixes these errors and also makes it write only the selected HPTE, not the whole group, since only the selected HPTE has been modified. This also micro-optimizes the calculations involving pte_index and i. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf --- arch/powerpc/kvm/book3s_pr_papr.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c index da0e0bc268bd..38f189975fe1 100644 --- a/arch/powerpc/kvm/book3s_pr_papr.c +++ b/arch/powerpc/kvm/book3s_pr_papr.c @@ -21,6 +21,8 @@ #include #include +#define HPTE_SIZE 16 /* bytes per HPT entry */ + static unsigned long get_pteg_addr(struct kvm_vcpu *vcpu, long pte_index) { struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu); @@ -40,32 +42,39 @@ static int kvmppc_h_pr_enter(struct kvm_vcpu *vcpu) long pte_index = kvmppc_get_gpr(vcpu, 5); unsigned long pteg[2 * 8]; unsigned long pteg_addr, i, *hpte; + long int ret; + i = pte_index & 7; pte_index &= ~7UL; pteg_addr = get_pteg_addr(vcpu, pte_index); copy_from_user(pteg, (void __user *)pteg_addr, sizeof(pteg)); hpte = pteg; + ret = H_PTEG_FULL; if (likely((flags & H_EXACT) == 0)) { - pte_index &= ~7UL; for (i = 0; ; ++i) { if (i == 8) - return H_PTEG_FULL; + goto done; if ((*hpte & HPTE_V_VALID) == 0) break; hpte += 2; } } else { - i = kvmppc_get_gpr(vcpu, 5) & 7UL; hpte += i * 2; + if (*hpte & HPTE_V_VALID) + goto done; } hpte[0] = kvmppc_get_gpr(vcpu, 6); hpte[1] = kvmppc_get_gpr(vcpu, 7); - copy_to_user((void __user *)pteg_addr, pteg, sizeof(pteg)); - kvmppc_set_gpr(vcpu, 3, H_SUCCESS); + pteg_addr += i * HPTE_SIZE; + copy_to_user((void __user *)pteg_addr, hpte, HPTE_SIZE); kvmppc_set_gpr(vcpu, 4, pte_index | i); + ret = H_SUCCESS; + + done: + kvmppc_set_gpr(vcpu, 3, ret); return EMULATE_DONE; } -- 2.20.1