Merge tag 'kvm-5.6-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "This is the first batch of KVM changes.

  ARM:
   - cleanups and corner case fixes.

  PPC:
   - Bugfixes

  x86:
   - Support for mapping DAX areas with large nested page table entries.

   - Cleanups and bugfixes here too. A particularly important one is a
     fix for FPU load when the thread has TIF_NEED_FPU_LOAD. There is
     also a race condition which could be used in guest userspace to
     exploit the guest kernel, for which the embargo expired today.

   - Fast path for IPI delivery vmexits, shaving about 200 clock cycles
     from IPI latency.

   - Protect against "Spectre-v1/L1TF" (bring data in the cache via
     speculative out of bound accesses, use L1TF on the sibling
     hyperthread to read it), which unfortunately is an even bigger
     whack-a-mole game than SpectreV1.

  Sean continues his mission to rewrite KVM. In addition to a sizable
  number of x86 patches, this time he contributed a pretty large
  refactoring of vCPU creation that affects all architectures but should
  not have any visible effect.

  s390 will come next week together with some more x86 patches"

* tag 'kvm-5.6-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits)
  x86/KVM: Clean up host's steal time structure
  x86/KVM: Make sure KVM_VCPU_FLUSH_TLB flag is not missed
  x86/kvm: Cache gfn to pfn translation
  x86/kvm: Introduce kvm_(un)map_gfn()
  x86/kvm: Be careful not to clear KVM_VCPU_FLUSH_TLB bit
  KVM: PPC: Book3S PR: Fix -Werror=return-type build failure
  KVM: PPC: Book3S HV: Release lock on page-out failure path
  KVM: arm64: Treat emulated TVAL TimerValue as a signed 32-bit integer
  KVM: arm64: pmu: Only handle supported event counters
  KVM: arm64: pmu: Fix chained SW_INCR counters
  KVM: arm64: pmu: Don't mark a counter as chained if the odd one is disabled
  KVM: arm64: pmu: Don't increment SW_INCR if PMCR.E is unset
  KVM: x86: Use a typedef for fastop functions
  KVM: X86: Add 'else' to unify fastop and execute call path
  KVM: x86: inline memslot_valid_for_gpte
  KVM: x86/mmu: Use huge pages for DAX-backed files
  KVM: x86/mmu: Remove lpage_is_disallowed() check from set_spte()
  KVM: x86/mmu: Fold max_mapping_level() into kvm_mmu_hugepage_adjust()
  KVM: x86/mmu: Zap any compound page when collapsing sptes
  KVM: x86/mmu: Remove obsolete gfn restoration in FNAME(fetch)
  ...

1 files changed, 85 insertions, 48 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 952d1a4f4d7e..ddbc61984227 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -22,6 +22,7 @@
 #include "kvm_cache_regs.h"
 #include <asm/kvm_emulate.h>
 #include <linux/stringify.h>
+#include <asm/fpu/api.h>
 #include <asm/debugreg.h>
 #include <asm/nospec-branch.h>
 
@@ -310,7 +311,9 @@ static void invalidate_registers(struct x86_emulate_ctxt *ctxt)
 #define ON64(x)
 #endif
 
-static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *));
+typedef void (*fastop_t)(struct fastop *);
+
+static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop);
 
 #define __FOP_FUNC(name) \
 	".align " __stringify(FASTOP_SIZE) " \n\t" \
@@ -1075,8 +1078,23 @@ static void fetch_register_operand(struct operand *op)
 	}
 }
 
-static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
+static void emulator_get_fpu(void)
+{
+	fpregs_lock();
+
+	fpregs_assert_state_consistent();
+	if (test_thread_flag(TIF_NEED_FPU_LOAD))
+		switch_fpu_return();
+}
+
+static void emulator_put_fpu(void)
 {
+	fpregs_unlock();
+}
+
+static void read_sse_reg(sse128_t *data, int reg)
+{
+	emulator_get_fpu();
 	switch (reg) {
 	case 0: asm("movdqa %%xmm0, %0" : "=m"(*data)); break;
 	case 1: asm("movdqa %%xmm1, %0" : "=m"(*data)); break;
@@ -1098,11 +1116,12 @@ static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
 #endif
 	default: BUG();
 	}
+	emulator_put_fpu();
 }
 
-static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
-			  int reg)
+static void write_sse_reg(sse128_t *data, int reg)
 {
+	emulator_get_fpu();
 	switch (reg) {
 	case 0: asm("movdqa %0, %%xmm0" : : "m"(*data)); break;
 	case 1: asm("movdqa %0, %%xmm1" : : "m"(*data)); break;
@@ -1124,10 +1143,12 @@ static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
 #endif
 	default: BUG();
 	}
+	emulator_put_fpu();
 }
 
-static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
+static void read_mmx_reg(u64 *data, int reg)
 {
+	emulator_get_fpu();
 	switch (reg) {
 	case 0: asm("movq %%mm0, %0" : "=m"(*data)); break;
 	case 1: asm("movq %%mm1, %0" : "=m"(*data)); break;
@@ -1139,10 +1160,12 @@ static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
 	case 7: asm("movq %%mm7, %0" : "=m"(*data)); break;
 	default: BUG();
 	}
+	emulator_put_fpu();
 }
 
-static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
+static void write_mmx_reg(u64 *data, int reg)
 {
+	emulator_get_fpu();
 	switch (reg) {
 	case 0: asm("movq %0, %%mm0" : : "m"(*data)); break;
 	case 1: asm("movq %0, %%mm1" : : "m"(*data)); break;
@@ -1154,6 +1177,7 @@ static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
 	case 7: asm("movq %0, %%mm7" : : "m"(*data)); break;
 	default: BUG();
 	}
+	emulator_put_fpu();
 }
 
 static int em_fninit(struct x86_emulate_ctxt *ctxt)
@@ -1161,7 +1185,9 @@ static int em_fninit(struct x86_emulate_ctxt *ctxt)
 	if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
 		return emulate_nm(ctxt);
 
+	emulator_get_fpu();
 	asm volatile("fninit");
+	emulator_put_fpu();
 	return X86EMUL_CONTINUE;
 }
 
@@ -1172,7 +1198,9 @@ static int em_fnstcw(struct x86_emulate_ctxt *ctxt)
 	if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
 		return emulate_nm(ctxt);
 
+	emulator_get_fpu();
 	asm volatile("fnstcw %0": "+m"(fcw));
+	emulator_put_fpu();
 
 	ctxt->dst.val = fcw;
 
@@ -1186,7 +1214,9 @@ static int em_fnstsw(struct x86_emulate_ctxt *ctxt)
 	if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
 		return emulate_nm(ctxt);
 
+	emulator_get_fpu();
 	asm volatile("fnstsw %0": "+m"(fsw));
+	emulator_put_fpu();
 
 	ctxt->dst.val = fsw;
 
@@ -1205,7 +1235,7 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
 		op->type = OP_XMM;
 		op->bytes = 16;
 		op->addr.xmm = reg;
-		read_sse_reg(ctxt, &op->vec_val, reg);
+		read_sse_reg(&op->vec_val, reg);
 		return;
 	}
 	if (ctxt->d & Mmx) {
@@ -1256,7 +1286,7 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
 			op->type = OP_XMM;
 			op->bytes = 16;
 			op->addr.xmm = ctxt->modrm_rm;
-			read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm);
+			read_sse_reg(&op->vec_val, ctxt->modrm_rm);
 			return rc;
 		}
 		if (ctxt->d & Mmx) {
@@ -1833,10 +1863,10 @@ static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op)
 				       op->bytes * op->count);
 		break;
 	case OP_XMM:
-		write_sse_reg(ctxt, &op->vec_val, op->addr.xmm);
+		write_sse_reg(&op->vec_val, op->addr.xmm);
 		break;
 	case OP_MM:
-		write_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
+		write_mmx_reg(&op->mm_val, op->addr.mm);
 		break;
 	case OP_NONE:
 		/* no writeback */
@@ -2348,12 +2378,7 @@ static int em_lseg(struct x86_emulate_ctxt *ctxt)
 static int emulator_has_longmode(struct x86_emulate_ctxt *ctxt)
 {
 #ifdef CONFIG_X86_64
-	u32 eax, ebx, ecx, edx;
-
-	eax = 0x80000001;
-	ecx = 0;
-	ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false);
-	return edx & bit(X86_FEATURE_LM);
+	return ctxt->ops->guest_has_long_mode(ctxt);
 #else
 	return false;
 #endif
@@ -3618,18 +3643,11 @@ static int em_mov(struct x86_emulate_ctxt *ctxt)
 	return X86EMUL_CONTINUE;
 }
 
-#define FFL(x) bit(X86_FEATURE_##x)
-
 static int em_movbe(struct x86_emulate_ctxt *ctxt)
 {
-	u32 ebx, ecx, edx, eax = 1;
 	u16 tmp;
 
-	/*
-	 * Check MOVBE is set in the guest-visible CPUID leaf.
-	 */
-	ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false);
-	if (!(ecx & FFL(MOVBE)))
+	if (!ctxt->ops->guest_has_movbe(ctxt))
 		return emulate_ud(ctxt);
 
 	switch (ctxt->op_bytes) {
@@ -4027,10 +4045,7 @@ static int em_movsxd(struct x86_emulate_ctxt *ctxt)
 
 static int check_fxsr(struct x86_emulate_ctxt *ctxt)
 {
-	u32 eax = 1, ebx, ecx = 0, edx;
-
-	ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false);
-	if (!(edx & FFL(FXSR)))
+	if (!ctxt->ops->guest_has_fxsr(ctxt))
 		return emulate_ud(ctxt);
 
 	if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
@@ -4092,8 +4107,12 @@ static int em_fxsave(struct x86_emulate_ctxt *ctxt)
 	if (rc != X86EMUL_CONTINUE)
 		return rc;
 
+	emulator_get_fpu();
+
 	rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_state));
 
+	emulator_put_fpu();
+
 	if (rc != X86EMUL_CONTINUE)
 		return rc;
 
@@ -4136,6 +4155,8 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt)
 	if (rc != X86EMUL_CONTINUE)
 		return rc;
 
+	emulator_get_fpu();
+
 	if (size < __fxstate_size(16)) {
 		rc = fxregs_fixup(&fx_state, size);
 		if (rc != X86EMUL_CONTINUE)
@@ -4151,6 +4172,8 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt)
 		rc = asm_safe("fxrstor %[fx]", : [fx] "m"(fx_state));
 
 out:
+	emulator_put_fpu();
+
 	return rc;
 }
 
@@ -5210,16 +5233,28 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
 				ctxt->ad_bytes = def_ad_bytes ^ 6;
 			break;
 		case 0x26:	/* ES override */
+			has_seg_override = true;
+			ctxt->seg_override = VCPU_SREG_ES;
+			break;
 		case 0x2e:	/* CS override */
+			has_seg_override = true;
+			ctxt->seg_override = VCPU_SREG_CS;
+			break;
 		case 0x36:	/* SS override */
+			has_seg_override = true;
+			ctxt->seg_override = VCPU_SREG_SS;
+			break;
 		case 0x3e:	/* DS override */
 			has_seg_override = true;
-			ctxt->seg_override = (ctxt->b >> 3) & 3;
+			ctxt->seg_override = VCPU_SREG_DS;
 			break;
 		case 0x64:	/* FS override */
+			has_seg_override = true;
+			ctxt->seg_override = VCPU_SREG_FS;
+			break;
 		case 0x65:	/* GS override */
 			has_seg_override = true;
-			ctxt->seg_override = ctxt->b & 7;
+			ctxt->seg_override = VCPU_SREG_GS;
 			break;
 		case 0x40 ... 0x4f: /* REX */
 			if (mode != X86EMUL_MODE_PROT64)
@@ -5303,10 +5338,15 @@ done_prefixes:
 			}
 			break;
 		case Escape:
-			if (ctxt->modrm > 0xbf)
-				opcode = opcode.u.esc->high[ctxt->modrm - 0xc0];
-			else
+			if (ctxt->modrm > 0xbf) {
+				size_t size = ARRAY_SIZE(opcode.u.esc->high);
+				u32 index = array_index_nospec(
+					ctxt->modrm - 0xc0, size);
+
+				opcode = opcode.u.esc->high[index];
+			} else {
 				opcode = opcode.u.esc->op[(ctxt->modrm >> 3) & 7];
+			}
 			break;
 		case InstrDual:
 			if ((ctxt->modrm >> 6) == 3)
@@ -5448,7 +5488,9 @@ static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt)
 {
 	int rc;
 
+	emulator_get_fpu();
 	rc = asm_safe("fwait");
+	emulator_put_fpu();
 
 	if (unlikely(rc != X86EMUL_CONTINUE))
 		return emulate_exception(ctxt, MF_VECTOR, 0, false);
@@ -5456,14 +5498,13 @@ static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt)
 	return X86EMUL_CONTINUE;
 }
 
-static void fetch_possible_mmx_operand(struct x86_emulate_ctxt *ctxt,
-				       struct operand *op)
+static void fetch_possible_mmx_operand(struct operand *op)
 {
 	if (op->type == OP_MM)
-		read_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
+		read_mmx_reg(&op->mm_val, op->addr.mm);
 }
 
-static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *))
+static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop)
 {
 	ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF;
 
@@ -5539,10 +5580,10 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 			 * Now that we know the fpu is exception safe, we can fetch
 			 * operands from it.
 			 */
-			fetch_possible_mmx_operand(ctxt, &ctxt->src);
-			fetch_possible_mmx_operand(ctxt, &ctxt->src2);
+			fetch_possible_mmx_operand(&ctxt->src);
+			fetch_possible_mmx_operand(&ctxt->src2);
 			if (!(ctxt->d & Mov))
-				fetch_possible_mmx_operand(ctxt, &ctxt->dst);
+				fetch_possible_mmx_operand(&ctxt->dst);
 		}
 
 		if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && ctxt->intercept) {
@@ -5641,14 +5682,10 @@ special_insn:
 		ctxt->eflags &= ~X86_EFLAGS_RF;
 
 	if (ctxt->execute) {
-		if (ctxt->d & Fastop) {
-			void (*fop)(struct fastop *) = (void *)ctxt->execute;
-			rc = fastop(ctxt, fop);
-			if (rc != X86EMUL_CONTINUE)
-				goto done;
-			goto writeback;
-		}
-		rc = ctxt->execute(ctxt);
+		if (ctxt->d & Fastop)
+			rc = fastop(ctxt, (fastop_t)ctxt->execute);
+		else
+			rc = ctxt->execute(ctxt);
 		if (rc != X86EMUL_CONTINUE)
 			goto done;
 		goto writeback;