[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [V2 PATCH 7/9] x86/hvm: pkeys, add pkeys support for guest_walk_tables
This patch adds pkeys support for guest_walk_tables. Signed-off-by: Huaitong Han <huaitong.han@xxxxxxxxx> --- xen/arch/x86/mm/guest_walk.c | 65 +++++++++++++++++++++++++++++++++++++++++++ xen/include/asm-x86/hvm/hvm.h | 2 ++ 2 files changed, 67 insertions(+) diff --git a/xen/arch/x86/mm/guest_walk.c b/xen/arch/x86/mm/guest_walk.c index 18d1acf..3e443b3 100644 --- a/xen/arch/x86/mm/guest_walk.c +++ b/xen/arch/x86/mm/guest_walk.c @@ -31,6 +31,8 @@ asm(".file \"" __OBJECT_FILE__ "\""); #include <xen/sched.h> #include <asm/page.h> #include <asm/guest_pt.h> +#include <asm/xstate.h> +#include <asm/i387.h> extern const uint32_t gw_page_flags[]; #if GUEST_PAGING_LEVELS == CONFIG_PAGING_LEVELS @@ -90,6 +92,53 @@ static uint32_t set_ad_bits(void *guest_p, void *walk_p, int set_dirty) return 0; } +#if GUEST_PAGING_LEVELS >= 4 +uint32_t leaf_pte_pkeys_check(struct vcpu *vcpu, uint32_t pfec, + uint32_t pte_access, uint32_t pte_pkeys) +{ + bool_t pkru_ad, pkru_wd; + bool_t ff, wf, uf, rsvdf, pkuf; + unsigned int pkru = 0; + + uf = pfec & PFEC_user_mode; + wf = pfec & PFEC_write_access; + rsvdf = pfec & PFEC_reserved_bit; + ff = pfec & PFEC_insn_fetch; + pkuf = pfec & PFEC_prot_key; + + if ( !cpu_has_xsave || !pkuf || is_pv_vcpu(vcpu) ) + return 0; + + vcpu_save_fpu(vcpu); + pkru = *(unsigned int*)get_xsave_addr(vcpu->arch.xsave_area, XSTATE_PKRU); + if ( unlikely(pkru) ) + { + /* + * PKU: additional mechanism by which the paging controls + * access to user-mode addresses based on the value in the + * PKRU register. A fault is considered as a PKU violation if all + * of the following conditions are ture: + * 1.CR4_PKE=1. + * 2.EFER_LMA=1. + * 3.page is present with no reserved bit violations. + * 4.the access is not an instruction fetch. + * 5.the access is to a user page. + * 6.PKRU.AD=1 + * or The access is a data write and PKRU.WD=1 + * and either CR0.WP=1 or it is a user access. + */ + pkru_ad = READ_PKRU_AD(pkru, pte_pkeys); + pkru_wd = READ_PKRU_AD(pkru, pte_pkeys); + if ( hvm_pku_enabled(vcpu) && hvm_long_mode_enabled(vcpu) && + !rsvdf && !ff && (pkru_ad || + (pkru_wd && wf && (hvm_wp_enabled(vcpu) || uf)))) + return 1; + } + + return 0; +} +#endif + /* Walk the guest pagetables, after the manner of a hardware walker. */ /* Because the walk is essentially random, it can cause a deadlock * warning in the p2m locking code. Highly unlikely this is an actual @@ -106,6 +155,7 @@ guest_walk_tables(struct vcpu *v, struct p2m_domain *p2m, #if GUEST_PAGING_LEVELS >= 4 /* 64-bit only... */ guest_l3e_t *l3p = NULL; guest_l4e_t *l4p; + uint32_t pkeys; #endif uint32_t gflags, mflags, iflags, rc = 0; bool_t smep = 0, smap = 0; @@ -190,6 +240,7 @@ guest_walk_tables(struct vcpu *v, struct p2m_domain *p2m, goto out; /* Get the l3e and check its flags*/ gw->l3e = l3p[guest_l3_table_offset(va)]; + pkeys = guest_l3e_get_pkeys(gw->l3e); gflags = guest_l3e_get_flags(gw->l3e) ^ iflags; if ( !(gflags & _PAGE_PRESENT) ) { rc |= _PAGE_PRESENT; @@ -199,6 +250,9 @@ guest_walk_tables(struct vcpu *v, struct p2m_domain *p2m, pse1G = (gflags & _PAGE_PSE) && guest_supports_1G_superpages(v); + if (pse1G && leaf_pte_pkeys_check(v, pfec, gflags, pkeys)) + rc |= _PAGE_PKEY_BIT; + if ( pse1G ) { /* Generate a fake l1 table entry so callers don't all @@ -270,6 +324,12 @@ guest_walk_tables(struct vcpu *v, struct p2m_domain *p2m, pse2M = (gflags & _PAGE_PSE) && guest_supports_superpages(v); +#if GUEST_PAGING_LEVELS >= 4 + pkeys = guest_l2e_get_pkeys(gw->l2e); + if (pse2M && leaf_pte_pkeys_check(v, pfec, gflags, pkeys)) + rc |= _PAGE_PKEY_BIT; +#endif + if ( pse2M ) { /* Special case: this guest VA is in a PSE superpage, so there's @@ -330,6 +390,11 @@ guest_walk_tables(struct vcpu *v, struct p2m_domain *p2m, goto out; } rc |= ((gflags & mflags) ^ mflags); +#if GUEST_PAGING_LEVELS >= 4 + pkeys = guest_l1e_get_pkeys(gw->l1e); + if (leaf_pte_pkeys_check(v, pfec, gflags, pkeys)) + rc |= _PAGE_PKEY_BIT; +#endif } #if GUEST_PAGING_LEVELS >= 4 /* 64-bit only... */ diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h index da799a0..cfbb1ef 100644 --- a/xen/include/asm-x86/hvm/hvm.h +++ b/xen/include/asm-x86/hvm/hvm.h @@ -276,6 +276,8 @@ int hvm_girq_dest_2_vcpu_id(struct domain *d, uint8_t dest, uint8_t dest_mode); (hvm_paging_enabled(v) && ((v)->arch.hvm_vcpu.guest_cr[4] & X86_CR4_SMAP)) #define hvm_nx_enabled(v) \ (!!((v)->arch.hvm_vcpu.guest_efer & EFER_NX)) +#define hvm_pku_enabled(v) \ + (hvm_paging_enabled(v) && ((v)->arch.hvm_vcpu.guest_cr[4] & X86_CR4_PKE)) /* Can we use superpages in the HAP p2m table? */ #define hap_has_1gb (!!(hvm_funcs.hap_capabilities & HVM_HAP_SUPERPAGE_1GB)) -- 2.4.3 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |