From 3387e8743edb38ddc2d5715d167166cd6624e78d Mon Sep 17 00:00:00 2001 From: Andriy Gapon Date: Tue, 25 Oct 2016 10:34:14 +0000 Subject: [PATCH] vmm/svm: iopm_bitmap and msr_bitmap must be contiguous in physical memory To achieve that the whole svm_softc is allocated with contigmalloc now. It would be more effient to de-embed those arrays and allocate only them with contigmalloc. Previously, if malloc(9) used non-contiguous pages for the arrays, then random bits in physical pages next to the first page would be used to determine permissions for I/O port and MSR accesses. That could result in a guest dangerously modifying the host hardware configuration. One example is that sometimes NMI watchdog driver in a Linux guest would be able to configure a performance counter on a host system. The counter would generate an interrupt and if hwpmc(4) driver is loaded on the host, then the interrupt would be delivered as an NMI. Discussed with: jhb Reviewed by: grehan MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D8321 --- sys/amd64/vmm/amd/svm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/sys/amd64/vmm/amd/svm.c b/sys/amd64/vmm/amd/svm.c index bd70d1135b4..6826cd802e8 100644 --- a/sys/amd64/vmm/amd/svm.c +++ b/sys/amd64/vmm/amd/svm.c @@ -517,7 +517,8 @@ svm_vminit(struct vm *vm, pmap_t pmap) vm_paddr_t msrpm_pa, iopm_pa, pml4_pa; int i; - svm_sc = malloc(sizeof (struct svm_softc), M_SVM, M_WAITOK | M_ZERO); + svm_sc = contigmalloc(sizeof (*svm_sc), M_SVM, M_WAITOK | M_ZERO, + 0, BUS_SPACE_MAXADDR, PAGE_SIZE, 0); svm_sc->vm = vm; svm_sc->nptp = (vm_offset_t)vtophys(pmap->pm_pml4); @@ -2042,7 +2043,7 @@ svm_vmcleanup(void *arg) { struct svm_softc *sc = arg; - free(sc, M_SVM); + contigfree(sc, sizeof (*sc), M_SVM); } static register_t *