[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging] x86/vvmx: fix I/O and MSR bitmaps mapping
commit 5dbbaa0fe121716e868294ac67a3712007843352 Author: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx> AuthorDate: Wed Nov 14 10:23:23 2018 +0000 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Wed Nov 14 18:42:48 2018 +0000 x86/vvmx: fix I/O and MSR bitmaps mapping Currently Xen tries to map bitmaps during emulation of vmptrld and vmwrite. This is wrong: a guest can store arbitrary values in those fields. Make bitmaps mapping happen only during a nested vmentry and only if the appropriate execution controls are turned on by L1 hypervisor. For performance reasons, Xen maps bitmaps only: 1. During the first nested vmentry 2. After L1 has changed an appropriate vmcs field 3. After nvmx_purge_vvmcs() was previously called Signed-off-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx> Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx> --- xen/arch/x86/hvm/vmx/vvmx.c | 105 ++++++++++++++++++++++++++++---------------- 1 file changed, 68 insertions(+), 37 deletions(-) diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c index 610236e3f2..88021af0e1 100644 --- a/xen/arch/x86/hvm/vmx/vvmx.c +++ b/xen/arch/x86/hvm/vmx/vvmx.c @@ -707,6 +707,17 @@ static void __clear_current_vvmcs(struct vcpu *v) __vmpclear(nvcpu->nv_n2vmcx_pa); } +static void unmap_msr_bitmap(struct vcpu *v) +{ + struct nestedvmx *nvmx = &vcpu_2_nvmx(v); + + if ( nvmx->msrbitmap ) + { + hvm_unmap_guest_frame(nvmx->msrbitmap, 1); + nvmx->msrbitmap = NULL; + } +} + /* * Refreshes the MSR bitmap mapping for the current nested vcpu. Returns true * for a successful mapping, and returns false for MSR_BITMAP parameter errors @@ -717,12 +728,7 @@ static bool __must_check _map_msr_bitmap(struct vcpu *v) struct nestedvmx *nvmx = &vcpu_2_nvmx(v); uint64_t gpa; - if ( nvmx->msrbitmap ) - { - hvm_unmap_guest_frame(nvmx->msrbitmap, 1); - nvmx->msrbitmap = NULL; - } - + unmap_msr_bitmap(v); gpa = get_vvmcs(v, MSR_BITMAP); if ( !IS_ALIGNED(gpa, PAGE_SIZE) ) @@ -733,6 +739,17 @@ static bool __must_check _map_msr_bitmap(struct vcpu *v) return nvmx->msrbitmap != NULL; } +static void unmap_io_bitmap(struct vcpu *v, unsigned int idx) +{ + struct nestedvmx *nvmx = &vcpu_2_nvmx(v); + + if ( nvmx->iobitmap[idx] ) + { + hvm_unmap_guest_frame(nvmx->iobitmap[idx], 1); + nvmx->iobitmap[idx] = NULL; + } +} + static bool_t __must_check _map_io_bitmap(struct vcpu *v, u64 vmcs_reg) { struct nestedvmx *nvmx = &vcpu_2_nvmx(v); @@ -740,8 +757,7 @@ static bool_t __must_check _map_io_bitmap(struct vcpu *v, u64 vmcs_reg) int index; index = vmcs_reg == IO_BITMAP_A ? 0 : 1; - if (nvmx->iobitmap[index]) - hvm_unmap_guest_frame(nvmx->iobitmap[index], 1); + unmap_io_bitmap(v, index); gpa = get_vvmcs(v, vmcs_reg); nvmx->iobitmap[index] = hvm_map_guest_frame_ro(gpa >> PAGE_SHIFT, 1); @@ -756,7 +772,6 @@ static inline bool_t __must_check map_io_bitmap_all(struct vcpu *v) static void nvmx_purge_vvmcs(struct vcpu *v) { - struct nestedvmx *nvmx = &vcpu_2_nvmx(v); struct nestedvcpu *nvcpu = &vcpu_nestedhvm(v); int i; @@ -766,16 +781,11 @@ static void nvmx_purge_vvmcs(struct vcpu *v) nvcpu->nv_vvmcx = NULL; nvcpu->nv_vvmcxaddr = INVALID_PADDR; v->arch.hvm.vmx.vmcs_shadow_maddr = 0; - for (i=0; i<2; i++) { - if ( nvmx->iobitmap[i] ) { - hvm_unmap_guest_frame(nvmx->iobitmap[i], 1); - nvmx->iobitmap[i] = NULL; - } - } - if ( nvmx->msrbitmap ) { - hvm_unmap_guest_frame(nvmx->msrbitmap, 1); - nvmx->msrbitmap = NULL; - } + + for ( i = 0; i < 2; i++ ) + unmap_io_bitmap(v, i); + + unmap_msr_bitmap(v); } u64 nvmx_get_tsc_offset(struct vcpu *v) @@ -1546,20 +1556,34 @@ static void clear_vvmcs_launched(struct list_head *launched_list, } } -static int nvmx_vmresume(struct vcpu *v, struct cpu_user_regs *regs) +static enum vmx_insn_errno nvmx_vmresume(struct vcpu *v) { struct nestedvmx *nvmx = &vcpu_2_nvmx(v); struct nestedvcpu *nvcpu = &vcpu_nestedhvm(v); + unsigned int exec_ctrl; - /* check VMCS is valid and IO BITMAP is set */ - if ( vvmcx_valid(v) && - ((nvmx->iobitmap[0] && nvmx->iobitmap[1]) || - !(__n2_exec_control(v) & CPU_BASED_ACTIVATE_IO_BITMAP) ) ) - nvcpu->nv_vmentry_pending = 1; - else - vmfail_invalid(regs); + ASSERT(vvmcx_valid(v)); + exec_ctrl = __n2_exec_control(v); - return X86EMUL_OKAY; + if ( exec_ctrl & CPU_BASED_ACTIVATE_IO_BITMAP ) + { + if ( (nvmx->iobitmap[0] == NULL || nvmx->iobitmap[1] == NULL) && + !map_io_bitmap_all(v) ) + goto invalid_control_state; + } + + if ( exec_ctrl & CPU_BASED_ACTIVATE_MSR_BITMAP ) + { + if ( nvmx->msrbitmap == NULL && !_map_msr_bitmap(v) ) + goto invalid_control_state; + } + + nvcpu->nv_vmentry_pending = 1; + + return VMX_INSN_SUCCEED; + +invalid_control_state: + return VMX_INSN_INVALID_CONTROL_STATE; } static int nvmx_handle_vmresume(struct cpu_user_regs *regs) @@ -1568,6 +1592,7 @@ static int nvmx_handle_vmresume(struct cpu_user_regs *regs) struct vcpu *v = current; struct nestedvmx *nvmx = &vcpu_2_nvmx(v); unsigned long intr_shadow; + int rc; if ( !vvmcx_valid(v) ) { @@ -1589,7 +1614,12 @@ static int nvmx_handle_vmresume(struct cpu_user_regs *regs) vmfail_valid(regs, VMX_INSN_VMRESUME_NONLAUNCHED_VMCS); return X86EMUL_OKAY; } - return nvmx_vmresume(v,regs); + + rc = nvmx_vmresume(v); + if ( rc ) + vmfail_valid(regs, rc); + + return X86EMUL_OKAY; } static int nvmx_handle_vmlaunch(struct cpu_user_regs *regs) @@ -1621,13 +1651,16 @@ static int nvmx_handle_vmlaunch(struct cpu_user_regs *regs) return X86EMUL_OKAY; } else { - rc = nvmx_vmresume(v,regs); - if ( rc == X86EMUL_OKAY ) + rc = nvmx_vmresume(v); + if ( rc ) + vmfail_valid(regs, rc); + else { if ( set_vvmcs_launched(&nvmx->launched_list, PFN_DOWN(v->arch.hvm.vmx.vmcs_shadow_maddr)) < 0 ) return X86EMUL_UNHANDLEABLE; } + rc = X86EMUL_OKAY; } return rc; } @@ -1691,9 +1724,7 @@ static int nvmx_handle_vmptrld(struct cpu_user_regs *regs) vvmcx = NULL; } } - if ( !vvmcx || - !map_io_bitmap_all(v) || - !_map_msr_bitmap(v) ) + else { vmfail(regs, VMX_INSN_VMPTRLD_INVALID_PHYADDR); goto out; @@ -1869,13 +1900,13 @@ static int nvmx_handle_vmwrite(struct cpu_user_regs *regs) switch ( vmcs_encoding & ~VMCS_HIGH(0) ) { case IO_BITMAP_A: - okay = _map_io_bitmap(v, IO_BITMAP_A); + unmap_io_bitmap(v, 0); break; case IO_BITMAP_B: - okay = _map_io_bitmap(v, IO_BITMAP_B); + unmap_io_bitmap(v, 1); break; case MSR_BITMAP: - okay = _map_msr_bitmap(v); + unmap_msr_bitmap(v); break; } -- generated by git-patchbot for /home/xen/git/xen.git#staging _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog
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