diff options
Diffstat (limited to 'arch/mips/kvm/entry.c')
| -rw-r--r-- | arch/mips/kvm/entry.c | 160 |
1 files changed, 144 insertions, 16 deletions
diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c index 6a02b3a3fa65..c5b254c4d0da 100644 --- a/arch/mips/kvm/entry.c +++ b/arch/mips/kvm/entry.c @@ -12,8 +12,11 @@ */ #include <linux/kvm_host.h> +#include <linux/log2.h> +#include <asm/mmu_context.h> #include <asm/msa.h> #include <asm/setup.h> +#include <asm/tlbex.h> #include <asm/uasm.h> /* Register names */ @@ -50,6 +53,8 @@ /* Some CP0 registers */ #define C0_HWRENA 7, 0 #define C0_BADVADDR 8, 0 +#define C0_BADINSTR 8, 1 +#define C0_BADINSTRP 8, 2 #define C0_ENTRYHI 10, 0 #define C0_STATUS 12, 0 #define C0_CAUSE 13, 0 @@ -89,6 +94,21 @@ static void *kvm_mips_build_ret_from_exit(void *addr); static void *kvm_mips_build_ret_to_guest(void *addr); static void *kvm_mips_build_ret_to_host(void *addr); +/* + * The version of this function in tlbex.c uses current_cpu_type(), but for KVM + * we assume symmetry. + */ +static int c0_kscratch(void) +{ + switch (boot_cpu_type()) { + case CPU_XLP: + case CPU_XLR: + return 22; + default: + return 31; + } +} + /** * kvm_mips_entry_setup() - Perform global setup for entry code. * @@ -103,18 +123,21 @@ int kvm_mips_entry_setup(void) * We prefer to use KScratchN registers if they are available over the * defaults above, which may not work on all cores. */ - unsigned int kscratch_mask = cpu_data[0].kscratch_mask & 0xfc; + unsigned int kscratch_mask = cpu_data[0].kscratch_mask; + + if (pgd_reg != -1) + kscratch_mask &= ~BIT(pgd_reg); /* Pick a scratch register for storing VCPU */ if (kscratch_mask) { - scratch_vcpu[0] = 31; + scratch_vcpu[0] = c0_kscratch(); scratch_vcpu[1] = ffs(kscratch_mask) - 1; kscratch_mask &= ~BIT(scratch_vcpu[1]); } /* Pick a scratch register to use as a temp for saving state */ if (kscratch_mask) { - scratch_tmp[0] = 31; + scratch_tmp[0] = c0_kscratch(); scratch_tmp[1] = ffs(kscratch_mask) - 1; kscratch_mask &= ~BIT(scratch_tmp[1]); } @@ -130,7 +153,7 @@ static void kvm_mips_build_save_scratch(u32 **p, unsigned int tmp, 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) { + if (scratch_tmp[0] == c0_kscratch()) { UASM_i_MFC0(p, tmp, scratch_tmp[0], scratch_tmp[1]); UASM_i_SW(p, tmp, offsetof(struct pt_regs, cp0_cause), frame); } @@ -146,7 +169,7 @@ static void kvm_mips_build_restore_scratch(u32 **p, unsigned int tmp, UASM_i_LW(p, tmp, offsetof(struct pt_regs, cp0_epc), frame); UASM_i_MTC0(p, tmp, scratch_vcpu[0], scratch_vcpu[1]); - if (scratch_tmp[0] == 31) { + if (scratch_tmp[0] == c0_kscratch()) { UASM_i_LW(p, tmp, offsetof(struct pt_regs, cp0_cause), frame); UASM_i_MTC0(p, tmp, scratch_tmp[0], scratch_tmp[1]); } @@ -286,23 +309,26 @@ 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, - offsetof(struct kvm_vcpu_arch, guest_kernel_asid)); + UASM_i_ADDIU(&p, T1, K1, offsetof(struct kvm_vcpu_arch, + guest_kernel_mm.context.asid)); /* else user */ - UASM_i_ADDIU(&p, T1, K1, - offsetof(struct kvm_vcpu_arch, guest_user_asid)); + UASM_i_ADDIU(&p, T1, K1, offsetof(struct kvm_vcpu_arch, + guest_user_mm.context.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); - /* x4 */ - uasm_i_sll(&p, T2, T2, 2); + /* index the ASID array */ + uasm_i_sll(&p, T2, T2, ilog2(sizeof(long))); 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); + /* + * reuse ASID array offset + * cpuinfo_mips is a multiple of sizeof(long) + */ + uasm_i_addiu(&p, T3, ZERO, sizeof(struct cpuinfo_mips)/sizeof(long)); uasm_i_mul(&p, T2, T2, T3); UASM_i_LA_mostly(&p, AT, (long)&cpu_data[0].asid_mask); @@ -312,7 +338,20 @@ static void *kvm_mips_build_enter_guest(void *addr) #else uasm_i_andi(&p, K0, K0, MIPS_ENTRYHI_ASID); #endif - uasm_i_mtc0(&p, K0, C0_ENTRYHI); + + /* + * Set up KVM T&E GVA pgd. + * This does roughly the same as TLBMISS_HANDLER_SETUP_PGD(): + * - call tlbmiss_handler_setup_pgd(mm->pgd) + * - but skips write into CP0_PWBase for now + */ + UASM_i_LW(&p, A0, (int)offsetof(struct mm_struct, pgd) - + (int)offsetof(struct mm_struct, context.asid), T1); + + UASM_i_LA(&p, T9, (unsigned long)tlbmiss_handler_setup_pgd); + uasm_i_jalr(&p, RA, T9); + uasm_i_mtc0(&p, K0, C0_ENTRYHI); + uasm_i_ehb(&p); /* Disable RDHWR access */ @@ -348,6 +387,80 @@ static void *kvm_mips_build_enter_guest(void *addr) } /** + * kvm_mips_build_tlb_refill_exception() - Assemble TLB refill handler. + * @addr: Address to start writing code. + * @handler: Address of common handler (within range of @addr). + * + * Assemble TLB refill exception fast path handler for guest execution. + * + * Returns: Next address after end of written function. + */ +void *kvm_mips_build_tlb_refill_exception(void *addr, void *handler) +{ + u32 *p = addr; + struct uasm_label labels[2]; + struct uasm_reloc relocs[2]; + struct uasm_label *l = labels; + struct uasm_reloc *r = relocs; + + memset(labels, 0, sizeof(labels)); + memset(relocs, 0, sizeof(relocs)); + + /* Save guest k1 into scratch register */ + 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]); + + /* Save guest k0 into VCPU structure */ + UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu, arch.gprs[K0]), K1); + + /* + * Some of the common tlbex code uses current_cpu_type(). For KVM we + * assume symmetry and just disable preemption to silence the warning. + */ + preempt_disable(); + + /* + * Now for the actual refill bit. A lot of this can be common with the + * Linux TLB refill handler, however we don't need to handle so many + * cases. We only need to handle user mode refills, and user mode runs + * with 32-bit addressing. + * + * Therefore the branch to label_vmalloc generated by build_get_pmde64() + * that isn't resolved should never actually get taken and is harmless + * to leave in place for now. + */ + +#ifdef CONFIG_64BIT + build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */ +#else + build_get_pgde32(&p, K0, K1); /* get pgd in K1 */ +#endif + + /* we don't support huge pages yet */ + + build_get_ptep(&p, K0, K1); + build_update_entries(&p, K0, K1); + build_tlb_write_entry(&p, &l, &r, tlb_random); + + preempt_enable(); + + /* Get the VCPU pointer from the VCPU scratch register again */ + UASM_i_MFC0(&p, K1, scratch_vcpu[0], scratch_vcpu[1]); + + /* Restore the guest's k0/k1 registers */ + UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu, arch.gprs[K0]), K1); + uasm_i_ehb(&p); + UASM_i_MFC0(&p, K1, scratch_tmp[0], scratch_tmp[1]); + + /* Jump to guest */ + uasm_i_eret(&p); + + return p; +} + +/** * kvm_mips_build_exception() - Assemble first level guest exception handler. * @addr: Address to start writing code. * @handler: Address of common handler (within range of @addr). @@ -468,6 +581,18 @@ void *kvm_mips_build_exit(void *addr) uasm_i_mfc0(&p, K0, C0_CAUSE); uasm_i_sw(&p, K0, offsetof(struct kvm_vcpu_arch, host_cp0_cause), K1); + if (cpu_has_badinstr) { + uasm_i_mfc0(&p, K0, C0_BADINSTR); + uasm_i_sw(&p, K0, offsetof(struct kvm_vcpu_arch, + host_cp0_badinstr), K1); + } + + if (cpu_has_badinstrp) { + uasm_i_mfc0(&p, K0, C0_BADINSTRP); + uasm_i_sw(&p, K0, offsetof(struct kvm_vcpu_arch, + host_cp0_badinstrp), K1); + } + /* Now restore the host state just enough to run the handlers */ /* Switch EBASE to the one used by Linux */ @@ -521,6 +646,9 @@ void *kvm_mips_build_exit(void *addr) uasm_i_and(&p, V0, V0, AT); uasm_i_lui(&p, AT, ST0_CU0 >> 16); uasm_i_or(&p, V0, V0, AT); +#ifdef CONFIG_64BIT + uasm_i_ori(&p, V0, V0, ST0_SX | ST0_UX); +#endif uasm_i_mtc0(&p, V0, C0_STATUS); uasm_i_ehb(&p); @@ -643,7 +771,7 @@ static void *kvm_mips_build_ret_to_guest(void *addr) /* Setup status register for running guest in UM */ uasm_i_ori(&p, V1, V1, ST0_EXL | KSU_USER | ST0_IE); - UASM_i_LA(&p, AT, ~(ST0_CU0 | ST0_MX)); + UASM_i_LA(&p, AT, ~(ST0_CU0 | ST0_MX | ST0_SX | ST0_UX)); uasm_i_and(&p, V1, V1, AT); uasm_i_mtc0(&p, V1, C0_STATUS); uasm_i_ehb(&p); |