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Diffstat (limited to 'arch/powerpc/kvm/44x_tlb.c')
-rw-r--r--arch/powerpc/kvm/44x_tlb.c524
1 files changed, 524 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c
new file mode 100644
index 00000000..33aa715d
--- /dev/null
+++ b/arch/powerpc/kvm/44x_tlb.c
@@ -0,0 +1,524 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright IBM Corp. 2007
+ *
+ * Authors: Hollis Blanchard <hollisb@us.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/highmem.h>
+
+#include <asm/tlbflush.h>
+#include <asm/mmu-44x.h>
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_44x.h>
+#include "timing.h"
+
+#include "44x_tlb.h"
+#include "trace.h"
+
+#ifndef PPC44x_TLBE_SIZE
+#define PPC44x_TLBE_SIZE PPC44x_TLB_4K
+#endif
+
+#define PAGE_SIZE_4K (1<<12)
+#define PAGE_MASK_4K (~(PAGE_SIZE_4K - 1))
+
+#define PPC44x_TLB_UATTR_MASK \
+ (PPC44x_TLB_U0|PPC44x_TLB_U1|PPC44x_TLB_U2|PPC44x_TLB_U3)
+#define PPC44x_TLB_USER_PERM_MASK (PPC44x_TLB_UX|PPC44x_TLB_UR|PPC44x_TLB_UW)
+#define PPC44x_TLB_SUPER_PERM_MASK (PPC44x_TLB_SX|PPC44x_TLB_SR|PPC44x_TLB_SW)
+
+#ifdef DEBUG
+void kvmppc_dump_tlbs(struct kvm_vcpu *vcpu)
+{
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ struct kvmppc_44x_tlbe *tlbe;
+ int i;
+
+ printk("vcpu %d TLB dump:\n", vcpu->vcpu_id);
+ printk("| %2s | %3s | %8s | %8s | %8s |\n",
+ "nr", "tid", "word0", "word1", "word2");
+
+ for (i = 0; i < ARRAY_SIZE(vcpu_44x->guest_tlb); i++) {
+ tlbe = &vcpu_44x->guest_tlb[i];
+ if (tlbe->word0 & PPC44x_TLB_VALID)
+ printk(" G%2d | %02X | %08X | %08X | %08X |\n",
+ i, tlbe->tid, tlbe->word0, tlbe->word1,
+ tlbe->word2);
+ }
+}
+#endif
+
+static inline void kvmppc_44x_tlbie(unsigned int index)
+{
+ /* 0 <= index < 64, so the V bit is clear and we can use the index as
+ * word0. */
+ asm volatile(
+ "tlbwe %[index], %[index], 0\n"
+ :
+ : [index] "r"(index)
+ );
+}
+
+static inline void kvmppc_44x_tlbre(unsigned int index,
+ struct kvmppc_44x_tlbe *tlbe)
+{
+ asm volatile(
+ "tlbre %[word0], %[index], 0\n"
+ "mfspr %[tid], %[sprn_mmucr]\n"
+ "andi. %[tid], %[tid], 0xff\n"
+ "tlbre %[word1], %[index], 1\n"
+ "tlbre %[word2], %[index], 2\n"
+ : [word0] "=r"(tlbe->word0),
+ [word1] "=r"(tlbe->word1),
+ [word2] "=r"(tlbe->word2),
+ [tid] "=r"(tlbe->tid)
+ : [index] "r"(index),
+ [sprn_mmucr] "i"(SPRN_MMUCR)
+ : "cc"
+ );
+}
+
+static inline void kvmppc_44x_tlbwe(unsigned int index,
+ struct kvmppc_44x_tlbe *stlbe)
+{
+ unsigned long tmp;
+
+ asm volatile(
+ "mfspr %[tmp], %[sprn_mmucr]\n"
+ "rlwimi %[tmp], %[tid], 0, 0xff\n"
+ "mtspr %[sprn_mmucr], %[tmp]\n"
+ "tlbwe %[word0], %[index], 0\n"
+ "tlbwe %[word1], %[index], 1\n"
+ "tlbwe %[word2], %[index], 2\n"
+ : [tmp] "=&r"(tmp)
+ : [word0] "r"(stlbe->word0),
+ [word1] "r"(stlbe->word1),
+ [word2] "r"(stlbe->word2),
+ [tid] "r"(stlbe->tid),
+ [index] "r"(index),
+ [sprn_mmucr] "i"(SPRN_MMUCR)
+ );
+}
+
+static u32 kvmppc_44x_tlb_shadow_attrib(u32 attrib, int usermode)
+{
+ /* We only care about the guest's permission and user bits. */
+ attrib &= PPC44x_TLB_PERM_MASK|PPC44x_TLB_UATTR_MASK;
+
+ if (!usermode) {
+ /* Guest is in supervisor mode, so we need to translate guest
+ * supervisor permissions into user permissions. */
+ attrib &= ~PPC44x_TLB_USER_PERM_MASK;
+ attrib |= (attrib & PPC44x_TLB_SUPER_PERM_MASK) << 3;
+ }
+
+ /* Make sure host can always access this memory. */
+ attrib |= PPC44x_TLB_SX|PPC44x_TLB_SR|PPC44x_TLB_SW;
+
+ /* WIMGE = 0b00100 */
+ attrib |= PPC44x_TLB_M;
+
+ return attrib;
+}
+
+/* Load shadow TLB back into hardware. */
+void kvmppc_44x_tlb_load(struct kvm_vcpu *vcpu)
+{
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ int i;
+
+ for (i = 0; i <= tlb_44x_hwater; i++) {
+ struct kvmppc_44x_tlbe *stlbe = &vcpu_44x->shadow_tlb[i];
+
+ if (get_tlb_v(stlbe) && get_tlb_ts(stlbe))
+ kvmppc_44x_tlbwe(i, stlbe);
+ }
+}
+
+static void kvmppc_44x_tlbe_set_modified(struct kvmppc_vcpu_44x *vcpu_44x,
+ unsigned int i)
+{
+ vcpu_44x->shadow_tlb_mod[i] = 1;
+}
+
+/* Save hardware TLB to the vcpu, and invalidate all guest mappings. */
+void kvmppc_44x_tlb_put(struct kvm_vcpu *vcpu)
+{
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ int i;
+
+ for (i = 0; i <= tlb_44x_hwater; i++) {
+ struct kvmppc_44x_tlbe *stlbe = &vcpu_44x->shadow_tlb[i];
+
+ if (vcpu_44x->shadow_tlb_mod[i])
+ kvmppc_44x_tlbre(i, stlbe);
+
+ if (get_tlb_v(stlbe) && get_tlb_ts(stlbe))
+ kvmppc_44x_tlbie(i);
+ }
+}
+
+
+/* Search the guest TLB for a matching entry. */
+int kvmppc_44x_tlb_index(struct kvm_vcpu *vcpu, gva_t eaddr, unsigned int pid,
+ unsigned int as)
+{
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ int i;
+
+ /* XXX Replace loop with fancy data structures. */
+ for (i = 0; i < ARRAY_SIZE(vcpu_44x->guest_tlb); i++) {
+ struct kvmppc_44x_tlbe *tlbe = &vcpu_44x->guest_tlb[i];
+ unsigned int tid;
+
+ if (eaddr < get_tlb_eaddr(tlbe))
+ continue;
+
+ if (eaddr > get_tlb_end(tlbe))
+ continue;
+
+ tid = get_tlb_tid(tlbe);
+ if (tid && (tid != pid))
+ continue;
+
+ if (!get_tlb_v(tlbe))
+ continue;
+
+ if (get_tlb_ts(tlbe) != as)
+ continue;
+
+ return i;
+ }
+
+ return -1;
+}
+
+gpa_t kvmppc_mmu_xlate(struct kvm_vcpu *vcpu, unsigned int gtlb_index,
+ gva_t eaddr)
+{
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ struct kvmppc_44x_tlbe *gtlbe = &vcpu_44x->guest_tlb[gtlb_index];
+ unsigned int pgmask = get_tlb_bytes(gtlbe) - 1;
+
+ return get_tlb_raddr(gtlbe) | (eaddr & pgmask);
+}
+
+int kvmppc_mmu_itlb_index(struct kvm_vcpu *vcpu, gva_t eaddr)
+{
+ unsigned int as = !!(vcpu->arch.shared->msr & MSR_IS);
+
+ return kvmppc_44x_tlb_index(vcpu, eaddr, vcpu->arch.pid, as);
+}
+
+int kvmppc_mmu_dtlb_index(struct kvm_vcpu *vcpu, gva_t eaddr)
+{
+ unsigned int as = !!(vcpu->arch.shared->msr & MSR_DS);
+
+ return kvmppc_44x_tlb_index(vcpu, eaddr, vcpu->arch.pid, as);
+}
+
+void kvmppc_mmu_itlb_miss(struct kvm_vcpu *vcpu)
+{
+}
+
+void kvmppc_mmu_dtlb_miss(struct kvm_vcpu *vcpu)
+{
+}
+
+static void kvmppc_44x_shadow_release(struct kvmppc_vcpu_44x *vcpu_44x,
+ unsigned int stlb_index)
+{
+ struct kvmppc_44x_shadow_ref *ref = &vcpu_44x->shadow_refs[stlb_index];
+
+ if (!ref->page)
+ return;
+
+ /* Discard from the TLB. */
+ /* Note: we could actually invalidate a host mapping, if the host overwrote
+ * this TLB entry since we inserted a guest mapping. */
+ kvmppc_44x_tlbie(stlb_index);
+
+ /* Now release the page. */
+ if (ref->writeable)
+ kvm_release_page_dirty(ref->page);
+ else
+ kvm_release_page_clean(ref->page);
+
+ ref->page = NULL;
+
+ /* XXX set tlb_44x_index to stlb_index? */
+
+ trace_kvm_stlb_inval(stlb_index);
+}
+
+void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
+{
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ int i;
+
+ for (i = 0; i <= tlb_44x_hwater; i++)
+ kvmppc_44x_shadow_release(vcpu_44x, i);
+}
+
+/**
+ * kvmppc_mmu_map -- create a host mapping for guest memory
+ *
+ * If the guest wanted a larger page than the host supports, only the first
+ * host page is mapped here and the rest are demand faulted.
+ *
+ * If the guest wanted a smaller page than the host page size, we map only the
+ * guest-size page (i.e. not a full host page mapping).
+ *
+ * Caller must ensure that the specified guest TLB entry is safe to insert into
+ * the shadow TLB.
+ */
+void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 gvaddr, gpa_t gpaddr,
+ unsigned int gtlb_index)
+{
+ struct kvmppc_44x_tlbe stlbe;
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ struct kvmppc_44x_tlbe *gtlbe = &vcpu_44x->guest_tlb[gtlb_index];
+ struct kvmppc_44x_shadow_ref *ref;
+ struct page *new_page;
+ hpa_t hpaddr;
+ gfn_t gfn;
+ u32 asid = gtlbe->tid;
+ u32 flags = gtlbe->word2;
+ u32 max_bytes = get_tlb_bytes(gtlbe);
+ unsigned int victim;
+
+ /* Select TLB entry to clobber. Indirectly guard against races with the TLB
+ * miss handler by disabling interrupts. */
+ local_irq_disable();
+ victim = ++tlb_44x_index;
+ if (victim > tlb_44x_hwater)
+ victim = 0;
+ tlb_44x_index = victim;
+ local_irq_enable();
+
+ /* Get reference to new page. */
+ gfn = gpaddr >> PAGE_SHIFT;
+ new_page = gfn_to_page(vcpu->kvm, gfn);
+ if (is_error_page(new_page)) {
+ printk(KERN_ERR "Couldn't get guest page for gfn %llx!\n",
+ (unsigned long long)gfn);
+ kvm_release_page_clean(new_page);
+ return;
+ }
+ hpaddr = page_to_phys(new_page);
+
+ /* Invalidate any previous shadow mappings. */
+ kvmppc_44x_shadow_release(vcpu_44x, victim);
+
+ /* XXX Make sure (va, size) doesn't overlap any other
+ * entries. 440x6 user manual says the result would be
+ * "undefined." */
+
+ /* XXX what about AS? */
+
+ /* Force TS=1 for all guest mappings. */
+ stlbe.word0 = PPC44x_TLB_VALID | PPC44x_TLB_TS;
+
+ if (max_bytes >= PAGE_SIZE) {
+ /* Guest mapping is larger than or equal to host page size. We can use
+ * a "native" host mapping. */
+ stlbe.word0 |= (gvaddr & PAGE_MASK) | PPC44x_TLBE_SIZE;
+ } else {
+ /* Guest mapping is smaller than host page size. We must restrict the
+ * size of the mapping to be at most the smaller of the two, but for
+ * simplicity we fall back to a 4K mapping (this is probably what the
+ * guest is using anyways). */
+ stlbe.word0 |= (gvaddr & PAGE_MASK_4K) | PPC44x_TLB_4K;
+
+ /* 'hpaddr' is a host page, which is larger than the mapping we're
+ * inserting here. To compensate, we must add the in-page offset to the
+ * sub-page. */
+ hpaddr |= gpaddr & (PAGE_MASK ^ PAGE_MASK_4K);
+ }
+
+ stlbe.word1 = (hpaddr & 0xfffffc00) | ((hpaddr >> 32) & 0xf);
+ stlbe.word2 = kvmppc_44x_tlb_shadow_attrib(flags,
+ vcpu->arch.shared->msr & MSR_PR);
+ stlbe.tid = !(asid & 0xff);
+
+ /* Keep track of the reference so we can properly release it later. */
+ ref = &vcpu_44x->shadow_refs[victim];
+ ref->page = new_page;
+ ref->gtlb_index = gtlb_index;
+ ref->writeable = !!(stlbe.word2 & PPC44x_TLB_UW);
+ ref->tid = stlbe.tid;
+
+ /* Insert shadow mapping into hardware TLB. */
+ kvmppc_44x_tlbe_set_modified(vcpu_44x, victim);
+ kvmppc_44x_tlbwe(victim, &stlbe);
+ trace_kvm_stlb_write(victim, stlbe.tid, stlbe.word0, stlbe.word1,
+ stlbe.word2);
+}
+
+/* For a particular guest TLB entry, invalidate the corresponding host TLB
+ * mappings and release the host pages. */
+static void kvmppc_44x_invalidate(struct kvm_vcpu *vcpu,
+ unsigned int gtlb_index)
+{
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(vcpu_44x->shadow_refs); i++) {
+ struct kvmppc_44x_shadow_ref *ref = &vcpu_44x->shadow_refs[i];
+ if (ref->gtlb_index == gtlb_index)
+ kvmppc_44x_shadow_release(vcpu_44x, i);
+ }
+}
+
+void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 old_msr)
+{
+ int usermode = vcpu->arch.shared->msr & MSR_PR;
+
+ vcpu->arch.shadow_pid = !usermode;
+}
+
+void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 new_pid)
+{
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ int i;
+
+ if (unlikely(vcpu->arch.pid == new_pid))
+ return;
+
+ vcpu->arch.pid = new_pid;
+
+ /* Guest userspace runs with TID=0 mappings and PID=0, to make sure it
+ * can't access guest kernel mappings (TID=1). When we switch to a new
+ * guest PID, which will also use host PID=0, we must discard the old guest
+ * userspace mappings. */
+ for (i = 0; i < ARRAY_SIZE(vcpu_44x->shadow_refs); i++) {
+ struct kvmppc_44x_shadow_ref *ref = &vcpu_44x->shadow_refs[i];
+
+ if (ref->tid == 0)
+ kvmppc_44x_shadow_release(vcpu_44x, i);
+ }
+}
+
+static int tlbe_is_host_safe(const struct kvm_vcpu *vcpu,
+ const struct kvmppc_44x_tlbe *tlbe)
+{
+ gpa_t gpa;
+
+ if (!get_tlb_v(tlbe))
+ return 0;
+
+ /* Does it match current guest AS? */
+ /* XXX what about IS != DS? */
+ if (get_tlb_ts(tlbe) != !!(vcpu->arch.shared->msr & MSR_IS))
+ return 0;
+
+ gpa = get_tlb_raddr(tlbe);
+ if (!gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT))
+ /* Mapping is not for RAM. */
+ return 0;
+
+ return 1;
+}
+
+int kvmppc_44x_emul_tlbwe(struct kvm_vcpu *vcpu, u8 ra, u8 rs, u8 ws)
+{
+ struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
+ struct kvmppc_44x_tlbe *tlbe;
+ unsigned int gtlb_index;
+
+ gtlb_index = kvmppc_get_gpr(vcpu, ra);
+ if (gtlb_index >= KVM44x_GUEST_TLB_SIZE) {
+ printk("%s: index %d\n", __func__, gtlb_index);
+ kvmppc_dump_vcpu(vcpu);
+ return EMULATE_FAIL;
+ }
+
+ tlbe = &vcpu_44x->guest_tlb[gtlb_index];
+
+ /* Invalidate shadow mappings for the about-to-be-clobbered TLB entry. */
+ if (tlbe->word0 & PPC44x_TLB_VALID)
+ kvmppc_44x_invalidate(vcpu, gtlb_index);
+
+ switch (ws) {
+ case PPC44x_TLB_PAGEID:
+ tlbe->tid = get_mmucr_stid(vcpu);
+ tlbe->word0 = kvmppc_get_gpr(vcpu, rs);
+ break;
+
+ case PPC44x_TLB_XLAT:
+ tlbe->word1 = kvmppc_get_gpr(vcpu, rs);
+ break;
+
+ case PPC44x_TLB_ATTRIB:
+ tlbe->word2 = kvmppc_get_gpr(vcpu, rs);
+ break;
+
+ default:
+ return EMULATE_FAIL;
+ }
+
+ if (tlbe_is_host_safe(vcpu, tlbe)) {
+ gva_t eaddr;
+ gpa_t gpaddr;
+ u32 bytes;
+
+ eaddr = get_tlb_eaddr(tlbe);
+ gpaddr = get_tlb_raddr(tlbe);
+
+ /* Use the advertised page size to mask effective and real addrs. */
+ bytes = get_tlb_bytes(tlbe);
+ eaddr &= ~(bytes - 1);
+ gpaddr &= ~(bytes - 1);
+
+ kvmppc_mmu_map(vcpu, eaddr, gpaddr, gtlb_index);
+ }
+
+ trace_kvm_gtlb_write(gtlb_index, tlbe->tid, tlbe->word0, tlbe->word1,
+ tlbe->word2);
+
+ kvmppc_set_exit_type(vcpu, EMULATED_TLBWE_EXITS);
+ return EMULATE_DONE;
+}
+
+int kvmppc_44x_emul_tlbsx(struct kvm_vcpu *vcpu, u8 rt, u8 ra, u8 rb, u8 rc)
+{
+ u32 ea;
+ int gtlb_index;
+ unsigned int as = get_mmucr_sts(vcpu);
+ unsigned int pid = get_mmucr_stid(vcpu);
+
+ ea = kvmppc_get_gpr(vcpu, rb);
+ if (ra)
+ ea += kvmppc_get_gpr(vcpu, ra);
+
+ gtlb_index = kvmppc_44x_tlb_index(vcpu, ea, pid, as);
+ if (rc) {
+ u32 cr = kvmppc_get_cr(vcpu);
+
+ if (gtlb_index < 0)
+ kvmppc_set_cr(vcpu, cr & ~0x20000000);
+ else
+ kvmppc_set_cr(vcpu, cr | 0x20000000);
+ }
+ kvmppc_set_gpr(vcpu, rt, gtlb_index);
+
+ kvmppc_set_exit_type(vcpu, EMULATED_TLBSX_EXITS);
+ return EMULATE_DONE;
+}
generated by cgit (git 2.34.1) at 2025-01-12 21:59:16 +0000