svn commit: r280929 - in head: lib/libvmmapi sys/amd64/include sys/amd64/vmm

Tycho Nightingale tychon at FreeBSD.org
Wed Apr 1 00:15:35 UTC 2015


Author: tychon
Date: Wed Apr  1 00:15:31 2015
New Revision: 280929
URL: https://svnweb.freebsd.org/changeset/base/280929

Log:
  Fix "MOVS" instruction memory to MMIO emulation.  Currently updates to
  %rdi, %rsi, etc are inadvertently bypassed along with the check to
  see if the instruction needs to be repeated per the 'rep' prefix.
  
  Add "MOVS" instruction support for the 'MMIO to MMIO' case.
  
  Reviewed by:	neel

Modified:
  head/lib/libvmmapi/vmmapi.c
  head/lib/libvmmapi/vmmapi.h
  head/sys/amd64/include/vmm_instruction_emul.h
  head/sys/amd64/vmm/vmm.c
  head/sys/amd64/vmm/vmm_dev.c
  head/sys/amd64/vmm/vmm_instruction_emul.c

Modified: head/lib/libvmmapi/vmmapi.c
==============================================================================
--- head/lib/libvmmapi/vmmapi.c	Wed Apr  1 00:00:17 2015	(r280928)
+++ head/lib/libvmmapi/vmmapi.c	Wed Apr  1 00:15:31 2015	(r280929)
@@ -979,6 +979,18 @@ gla2gpa(struct vmctx *ctx, int vcpu, str
 	return (error);
 }
 
+int
+vm_gla2gpa(struct vmctx *ctx, int vcpu, struct vm_guest_paging *paging,
+    uint64_t gla, int prot, uint64_t *gpa)
+{
+	int error, fault;
+
+	error = gla2gpa(ctx, vcpu, paging, gla, prot, &fault, gpa);
+	if (fault)
+		error = fault;
+	return (error);
+}
+
 #ifndef min
 #define	min(a,b)	(((a) < (b)) ? (a) : (b))
 #endif

Modified: head/lib/libvmmapi/vmmapi.h
==============================================================================
--- head/lib/libvmmapi/vmmapi.h	Wed Apr  1 00:00:17 2015	(r280928)
+++ head/lib/libvmmapi/vmmapi.h	Wed Apr  1 00:15:31 2015	(r280929)
@@ -63,6 +63,8 @@ int	vm_get_memory_seg(struct vmctx *ctx,
 int	vm_setup_memory(struct vmctx *ctx, size_t len, enum vm_mmap_style s);
 void	*vm_map_gpa(struct vmctx *ctx, vm_paddr_t gaddr, size_t len);
 int	vm_get_gpa_pmap(struct vmctx *, uint64_t gpa, uint64_t *pte, int *num);
+int	vm_gla2gpa(struct vmctx *, int vcpuid, struct vm_guest_paging *paging,
+		   uint64_t gla, int prot, uint64_t *gpa);
 uint32_t vm_get_lowmem_limit(struct vmctx *ctx);
 void	vm_set_lowmem_limit(struct vmctx *ctx, uint32_t limit);
 void	vm_set_memflags(struct vmctx *ctx, int flags);

Modified: head/sys/amd64/include/vmm_instruction_emul.h
==============================================================================
--- head/sys/amd64/include/vmm_instruction_emul.h	Wed Apr  1 00:00:17 2015	(r280928)
+++ head/sys/amd64/include/vmm_instruction_emul.h	Wed Apr  1 00:15:31 2015	(r280929)
@@ -90,7 +90,7 @@ int vmm_fetch_instruction(struct vm *vm,
  * Returns 1 if an exception was injected into the guest.
  * Returns -1 otherwise.
  */
-int vmm_gla2gpa(struct vm *vm, int vcpuid, struct vm_guest_paging *paging,
+int vm_gla2gpa(struct vm *vm, int vcpuid, struct vm_guest_paging *paging,
     uint64_t gla, int prot, uint64_t *gpa);
 
 void vie_init(struct vie *vie, const char *inst_bytes, int inst_length);

Modified: head/sys/amd64/vmm/vmm.c
==============================================================================
--- head/sys/amd64/vmm/vmm.c	Wed Apr  1 00:00:17 2015	(r280928)
+++ head/sys/amd64/vmm/vmm.c	Wed Apr  1 00:15:31 2015	(r280929)
@@ -2332,7 +2332,7 @@ vm_copy_setup(struct vm *vm, int vcpuid,
 	remaining = len;
 	while (remaining > 0) {
 		KASSERT(nused < num_copyinfo, ("insufficient vm_copyinfo"));
-		error = vmm_gla2gpa(vm, vcpuid, paging, gla, prot, &gpa);
+		error = vm_gla2gpa(vm, vcpuid, paging, gla, prot, &gpa);
 		if (error)
 			return (error);
 		off = gpa & PAGE_MASK;

Modified: head/sys/amd64/vmm/vmm_dev.c
==============================================================================
--- head/sys/amd64/vmm/vmm_dev.c	Wed Apr  1 00:00:17 2015	(r280928)
+++ head/sys/amd64/vmm/vmm_dev.c	Wed Apr  1 00:15:31 2015	(r280929)
@@ -440,10 +440,10 @@ vmmdev_ioctl(struct cdev *cdev, u_long c
 		CTASSERT(PROT_WRITE == VM_PROT_WRITE);
 		CTASSERT(PROT_EXEC == VM_PROT_EXECUTE);
 		gg = (struct vm_gla2gpa *)data;
-		error = vmm_gla2gpa(sc->vm, gg->vcpuid, &gg->paging, gg->gla,
+		error = vm_gla2gpa(sc->vm, gg->vcpuid, &gg->paging, gg->gla,
 		    gg->prot, &gg->gpa);
 		KASSERT(error == 0 || error == 1 || error == -1,
-		    ("%s: vmm_gla2gpa unknown error %d", __func__, error));
+		    ("%s: vm_gla2gpa unknown error %d", __func__, error));
 		if (error >= 0) {
 			/*
 			 * error = 0: the translation was successful

Modified: head/sys/amd64/vmm/vmm_instruction_emul.c
==============================================================================
--- head/sys/amd64/vmm/vmm_instruction_emul.c	Wed Apr  1 00:00:17 2015	(r280928)
+++ head/sys/amd64/vmm/vmm_instruction_emul.c	Wed Apr  1 00:15:31 2015	(r280929)
@@ -634,7 +634,7 @@ emulate_movs(void *vm, int vcpuid, uint6
 #else
 	struct iovec copyinfo[2];
 #endif
-	uint64_t dstaddr, srcaddr, val;
+	uint64_t dstaddr, srcaddr, dstgpa, srcgpa, val;
 	uint64_t rcx, rdi, rsi, rflags;
 	int error, opsize, seg, repeat;
 
@@ -669,7 +669,7 @@ emulate_movs(void *vm, int vcpuid, uint6
 	 * (1)  memory		memory		n/a
 	 * (2)  memory		mmio		emulated
 	 * (3)  mmio		memory		emulated
-	 * (4)  mmio		mmio		not emulated
+	 * (4)  mmio		mmio		emulated
 	 *
 	 * At this point we don't have sufficient information to distinguish
 	 * between (2), (3) and (4). We use 'vm_copy_setup()' to tease this
@@ -694,7 +694,8 @@ emulate_movs(void *vm, int vcpuid, uint6
 		vm_copyin(vm, vcpuid, copyinfo, &val, opsize);
 		vm_copy_teardown(vm, vcpuid, copyinfo, nitems(copyinfo));
 		error = memwrite(vm, vcpuid, gpa, val, opsize, arg);
-		goto done;
+		if (error)
+			goto done;
 	} else if (error > 0) {
 		/*
 		 * Resume guest execution to handle fault.
@@ -705,37 +706,55 @@ emulate_movs(void *vm, int vcpuid, uint6
 		 * 'vm_copy_setup()' is expected to fail for cases (3) and (4)
 		 * if 'srcaddr' is in the mmio space.
 		 */
-	}
-
-	error = get_gla(vm, vcpuid, vie, paging, opsize, vie->addrsize,
-	    PROT_WRITE, VM_REG_GUEST_ES, VM_REG_GUEST_RDI, &dstaddr);
-	if (error)
-		goto done;
 
-	error = vm_copy_setup(vm, vcpuid, paging, dstaddr, opsize,
-	    PROT_WRITE, copyinfo, nitems(copyinfo));
-	if (error == 0) {
-		/*
-		 * case (3): read from MMIO and write to system memory.
-		 *
-		 * A MMIO read can have side-effects so we commit to it
-		 * only after vm_copy_setup() is successful. If a page-fault
-		 * needs to be injected into the guest then it will happen
-		 * before the MMIO read is attempted.
-		 */
-		error = memread(vm, vcpuid, gpa, &val, opsize, arg);
+		error = get_gla(vm, vcpuid, vie, paging, opsize, vie->addrsize,
+		    PROT_WRITE, VM_REG_GUEST_ES, VM_REG_GUEST_RDI, &dstaddr);
 		if (error)
 			goto done;
 
-		vm_copyout(vm, vcpuid, &val, copyinfo, opsize);
-		vm_copy_teardown(vm, vcpuid, copyinfo, nitems(copyinfo));
-	} else if (error > 0) {
-		/*
-		 * Resume guest execution to handle fault.
-		 */
-		goto done;
-	} else {
-		goto done;
+		error = vm_copy_setup(vm, vcpuid, paging, dstaddr, opsize,
+		    PROT_WRITE, copyinfo, nitems(copyinfo));
+		if (error == 0) {
+			/*
+			 * case (3): read from MMIO and write to system memory.
+			 *
+			 * A MMIO read can have side-effects so we
+			 * commit to it only after vm_copy_setup() is
+			 * successful. If a page-fault needs to be
+			 * injected into the guest then it will happen
+			 * before the MMIO read is attempted.
+			 */
+			error = memread(vm, vcpuid, gpa, &val, opsize, arg);
+			if (error)
+				goto done;
+
+			vm_copyout(vm, vcpuid, &val, copyinfo, opsize);
+			vm_copy_teardown(vm, vcpuid, copyinfo, nitems(copyinfo));
+		} else if (error > 0) {
+			/*
+			 * Resume guest execution to handle fault.
+			 */
+			goto done;
+		} else {
+			/*
+			 * Case (4): read from and write to mmio.
+			 */
+			error = vm_gla2gpa(vm, vcpuid, paging, srcaddr,
+			    PROT_READ, &srcgpa);
+			if (error)
+				goto done;
+			error = memread(vm, vcpuid, srcgpa, &val, opsize, arg);
+			if (error)
+				goto done;
+
+			error = vm_gla2gpa(vm, vcpuid, paging, dstaddr,
+			   PROT_WRITE, &dstgpa);
+			if (error)
+				goto done;
+			error = memwrite(vm, vcpuid, dstgpa, val, opsize, arg);
+			if (error)
+				goto done;
+		}
 	}
 
 	error = vie_read_register(vm, vcpuid, VM_REG_GUEST_RSI, &rsi);
@@ -1465,7 +1484,7 @@ ptp_hold(struct vm *vm, vm_paddr_t ptpph
 }
 
 int
-vmm_gla2gpa(struct vm *vm, int vcpuid, struct vm_guest_paging *paging,
+vm_gla2gpa(struct vm *vm, int vcpuid, struct vm_guest_paging *paging,
     uint64_t gla, int prot, uint64_t *gpa)
 {
 	int nlevels, pfcode, ptpshift, ptpindex, retval, usermode, writable;


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