mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-14 13:33:30 -04:00
Code Issues Packages Projects Releases Wiki Activity

KVM: SVM: Add a helper to allocate and initialize permissions bitmaps

Browse Source 
Add a helper to allocate and initialize an MSR or I/O permissions map, as
the logic is identical between the two map types, the only difference is
the size of the bitmap.  Opportunistically add a comment to explain why
the bitmaps are initialized with 0xff, e.g. instead of the more common
zero-initialized behavior, which is the main motivation for deduplicating
the code.

No functional change intended.

Link: https://lore.kernel.org/r/20250610225737.156318-31-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson
2025-06-10 15:57:35 -07:00
parent 54f1c77061
commit 73be81b3bb
2 changed files with 22 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
arch/x86/kvm/svm/svm.c
View File

@@ -722,19 +722,23 @@ void svm_enable_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, int type)
svm->nested.force_msr_bitmap_recalc = true;
}
void *svm_vcpu_alloc_msrpm(void)
void *svm_alloc_permissions_map(unsigned long size, gfp_t gfp_mask)
{
unsigned int order = get_order(MSRPM_SIZE);
struct page *pages = alloc_pages(GFP_KERNEL_ACCOUNT, order);
void *msrpm;
unsigned int order = get_order(size);
struct page *pages = alloc_pages(gfp_mask, order);
void *pm;
if (!pages)
return NULL;
msrpm = page_address(pages);
memset(msrpm, 0xff, PAGE_SIZE * (1 << order));
/*
* Set all bits in the permissions map so that all MSR and I/O accesses
* are intercepted by default.
*/
pm = page_address(pages);
memset(pm, 0xff, PAGE_SIZE * (1 << order));
return msrpm;
return pm;
}
static void svm_recalc_lbr_msr_intercepts(struct kvm_vcpu *vcpu)
@@ -5314,11 +5318,8 @@ static __init void svm_set_cpu_caps(void)
static __init int svm_hardware_setup(void)
{
int cpu;
struct page *iopm_pages;
void *iopm_va;
int r;
unsigned int order = get_order(IOPM_SIZE);
int cpu, r;
/*
* NX is required for shadow paging and for NPT if the NX huge pages
@@ -5399,13 +5400,11 @@ static __init int svm_hardware_setup(void)
pr_info("LBR virtualization supported\n");
}
iopm_pages = alloc_pages(GFP_KERNEL, order);
if (!iopm_pages)
iopm_va = svm_alloc_permissions_map(IOPM_SIZE, GFP_KERNEL);
if (!iopm_va)
return -ENOMEM;
iopm_va = page_address(iopm_pages);
memset(iopm_va, 0xff, PAGE_SIZE * (1 << order));
iopm_base = __sme_page_pa(iopm_pages);
iopm_base = __sme_set(__pa(iopm_va));
/*
* Note, SEV setup consumes npt_enabled and enable_mmio_caching (which

8
arch/x86/kvm/svm/svm.h
View File

@@ -667,7 +667,13 @@ BUILD_SVM_MSR_BITMAP_HELPERS(void, set, __set)
/* svm.c */
extern bool dump_invalid_vmcb;
void *svm_vcpu_alloc_msrpm(void);
void *svm_alloc_permissions_map(unsigned long size, gfp_t gfp_mask);
static inline void *svm_vcpu_alloc_msrpm(void)
{
return svm_alloc_permissions_map(MSRPM_SIZE, GFP_KERNEL_ACCOUNT);
}
void svm_vcpu_free_msrpm(void *msrpm);
void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb);
void svm_enable_lbrv(struct kvm_vcpu *vcpu);