From e41637d85846b5b4b6ef5232a22b7e74c03f1be6 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Fri, 8 Jul 2016 11:53:23 +0100 Subject: [PATCH] MIPS: KVM: Make entry code MIPS64 friendly MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The MIPS KVM entry code (originally kvm_locore.S, later locore.S, and now entry.c) has never quite been right when built for 64-bit, using 32-bit instructions when 64-bit instructions were needed for handling 64-bit registers and pointers. Fix several cases of this now. The changes roughly fall into the following categories. - COP0 scratch registers contain guest register values and the VCPU pointer, and are themselves full width. Similarly CP0_EPC and CP0_BadVAddr registers are full width (even though technically we don't support 64-bit guest address spaces with trap & emulate KVM). Use MFC0/MTC0 for accessing them. - Handling of stack pointers and the VCPU pointer must match the pointer size of the kernel ABI (always o32 or n64), so use ADDIU. - The CPU number in thread_info, and the guest_{user,kernel}_asid arrays in kvm_vcpu_arch are all 32 bit integers, so use lw (instead of LW) to load them. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini --- arch/mips/kvm/entry.c | 48 +++++++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 24 deletions(-) diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c index 75ba7c2ecb3d..f4556d0279c6 100644 --- a/arch/mips/kvm/entry.c +++ b/arch/mips/kvm/entry.c @@ -120,12 +120,12 @@ static void kvm_mips_build_save_scratch(u32 **p, unsigned int tmp, unsigned int frame) { /* Save the VCPU scratch register value in cp0_epc of the stack frame */ - uasm_i_mfc0(p, tmp, scratch_vcpu[0], scratch_vcpu[1]); + UASM_i_MFC0(p, tmp, scratch_vcpu[0], scratch_vcpu[1]); UASM_i_SW(p, tmp, offsetof(struct pt_regs, cp0_epc), frame); /* Save the temp scratch register value in cp0_cause of stack frame */ if (scratch_tmp[0] == 31) { - uasm_i_mfc0(p, tmp, scratch_tmp[0], scratch_tmp[1]); + UASM_i_MFC0(p, tmp, scratch_tmp[0], scratch_tmp[1]); UASM_i_SW(p, tmp, offsetof(struct pt_regs, cp0_cause), frame); } } @@ -138,11 +138,11 @@ static void kvm_mips_build_restore_scratch(u32 **p, unsigned int tmp, * kvm_mips_build_save_scratch(). */ UASM_i_LW(p, tmp, offsetof(struct pt_regs, cp0_epc), frame); - uasm_i_mtc0(p, tmp, scratch_vcpu[0], scratch_vcpu[1]); + UASM_i_MTC0(p, tmp, scratch_vcpu[0], scratch_vcpu[1]); if (scratch_tmp[0] == 31) { UASM_i_LW(p, tmp, offsetof(struct pt_regs, cp0_cause), frame); - uasm_i_mtc0(p, tmp, scratch_tmp[0], scratch_tmp[1]); + UASM_i_MTC0(p, tmp, scratch_tmp[0], scratch_tmp[1]); } } @@ -171,7 +171,7 @@ void *kvm_mips_build_vcpu_run(void *addr) */ /* k0/k1 not being used in host kernel context */ - uasm_i_addiu(&p, K1, SP, -(int)sizeof(struct pt_regs)); + UASM_i_ADDIU(&p, K1, SP, -(int)sizeof(struct pt_regs)); for (i = 16; i < 32; ++i) { if (i == 24) i = 28; @@ -186,10 +186,10 @@ void *kvm_mips_build_vcpu_run(void *addr) kvm_mips_build_save_scratch(&p, V1, K1); /* VCPU scratch register has pointer to vcpu */ - uasm_i_mtc0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]); + UASM_i_MTC0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]); /* Offset into vcpu->arch */ - uasm_i_addiu(&p, K1, A1, offsetof(struct kvm_vcpu, arch)); + UASM_i_ADDIU(&p, K1, A1, offsetof(struct kvm_vcpu, arch)); /* * Save the host stack to VCPU, used for exception processing @@ -252,7 +252,7 @@ static void *kvm_mips_build_enter_guest(void *addr) /* Set Guest EPC */ UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, pc), K1); - uasm_i_mtc0(&p, T0, C0_EPC); + UASM_i_MTC0(&p, T0, C0_EPC); /* Set the ASID for the Guest Kernel */ UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, cop0), K1); @@ -261,20 +261,20 @@ static void *kvm_mips_build_enter_guest(void *addr) uasm_i_andi(&p, T0, T0, KSU_USER | ST0_ERL | ST0_EXL); uasm_i_xori(&p, T0, T0, KSU_USER); uasm_il_bnez(&p, &r, T0, label_kernel_asid); - uasm_i_addiu(&p, T1, K1, + UASM_i_ADDIU(&p, T1, K1, offsetof(struct kvm_vcpu_arch, guest_kernel_asid)); /* else user */ - uasm_i_addiu(&p, T1, K1, + UASM_i_ADDIU(&p, T1, K1, offsetof(struct kvm_vcpu_arch, guest_user_asid)); uasm_l_kernel_asid(&l, p); /* t1: contains the base of the ASID array, need to get the cpu id */ /* smp_processor_id */ - UASM_i_LW(&p, T2, offsetof(struct thread_info, cpu), GP); + uasm_i_lw(&p, T2, offsetof(struct thread_info, cpu), GP); /* x4 */ uasm_i_sll(&p, T2, T2, 2); UASM_i_ADDU(&p, T3, T1, T2); - UASM_i_LW(&p, K0, 0, T3); + uasm_i_lw(&p, K0, 0, T3); #ifdef CONFIG_MIPS_ASID_BITS_VARIABLE /* x sizeof(struct cpuinfo_mips)/4 */ uasm_i_addiu(&p, T3, ZERO, sizeof(struct cpuinfo_mips)/4); @@ -344,11 +344,11 @@ void *kvm_mips_build_exception(void *addr, void *handler) memset(relocs, 0, sizeof(relocs)); /* Save guest k1 into scratch register */ - uasm_i_mtc0(&p, K1, scratch_tmp[0], scratch_tmp[1]); + UASM_i_MTC0(&p, K1, scratch_tmp[0], scratch_tmp[1]); /* Get the VCPU pointer from the VCPU scratch register */ - uasm_i_mfc0(&p, K1, scratch_vcpu[0], scratch_vcpu[1]); - uasm_i_addiu(&p, K1, K1, offsetof(struct kvm_vcpu, arch)); + UASM_i_MFC0(&p, K1, scratch_vcpu[0], scratch_vcpu[1]); + UASM_i_ADDIU(&p, K1, K1, offsetof(struct kvm_vcpu, arch)); /* Save guest k0 into VCPU structure */ UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, gprs[K0]), K1); @@ -415,13 +415,13 @@ void *kvm_mips_build_exit(void *addr) /* Finally save guest k1 to VCPU */ uasm_i_ehb(&p); - uasm_i_mfc0(&p, T0, scratch_tmp[0], scratch_tmp[1]); + UASM_i_MFC0(&p, T0, scratch_tmp[0], scratch_tmp[1]); UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, gprs[K1]), K1); /* Now that context has been saved, we can use other registers */ /* Restore vcpu */ - uasm_i_mfc0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]); + UASM_i_MFC0(&p, A1, scratch_vcpu[0], scratch_vcpu[1]); uasm_i_move(&p, S1, A1); /* Restore run (vcpu->run) */ @@ -433,10 +433,10 @@ void *kvm_mips_build_exit(void *addr) * Save Host level EPC, BadVaddr and Cause to VCPU, useful to process * the exception */ - uasm_i_mfc0(&p, K0, C0_EPC); + UASM_i_MFC0(&p, K0, C0_EPC); UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, pc), K1); - uasm_i_mfc0(&p, K0, C0_BADVADDR); + UASM_i_MFC0(&p, K0, C0_BADVADDR); UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, host_cp0_badvaddr), K1); @@ -506,7 +506,7 @@ void *kvm_mips_build_exit(void *addr) UASM_i_LW(&p, SP, offsetof(struct kvm_vcpu_arch, host_stack), K1); /* Saved host state */ - uasm_i_addiu(&p, SP, SP, -(int)sizeof(struct pt_regs)); + UASM_i_ADDIU(&p, SP, SP, -(int)sizeof(struct pt_regs)); /* * XXXKYMA do we need to load the host ASID, maybe not because the @@ -529,7 +529,7 @@ void *kvm_mips_build_exit(void *addr) */ UASM_i_LA(&p, T9, (unsigned long)kvm_mips_handle_exit); uasm_i_jalr(&p, RA, T9); - uasm_i_addiu(&p, SP, SP, -CALLFRAME_SIZ); + UASM_i_ADDIU(&p, SP, SP, -CALLFRAME_SIZ); uasm_resolve_relocs(relocs, labels); @@ -569,7 +569,7 @@ static void *kvm_mips_build_ret_from_exit(void *addr) */ uasm_i_move(&p, K1, S1); - uasm_i_addiu(&p, K1, K1, offsetof(struct kvm_vcpu, arch)); + UASM_i_ADDIU(&p, K1, K1, offsetof(struct kvm_vcpu, arch)); /* * Check return value, should tell us if we are returning to the @@ -603,7 +603,7 @@ static void *kvm_mips_build_ret_to_guest(void *addr) u32 *p = addr; /* Put the saved pointer to vcpu (s1) back into the scratch register */ - uasm_i_mtc0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]); + UASM_i_MTC0(&p, S1, scratch_vcpu[0], scratch_vcpu[1]); /* Load up the Guest EBASE to minimize the window where BEV is set */ UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, guest_ebase), K1); @@ -645,7 +645,7 @@ static void *kvm_mips_build_ret_to_host(void *addr) /* EBASE is already pointing to Linux */ UASM_i_LW(&p, K1, offsetof(struct kvm_vcpu_arch, host_stack), K1); - uasm_i_addiu(&p, K1, K1, -(int)sizeof(struct pt_regs)); + UASM_i_ADDIU(&p, K1, K1, -(int)sizeof(struct pt_regs)); /* * r2/v0 is the return code, shift it down by 2 (arithmetic) -- 2.25.1